{"id":"F2006B02175","name":"AD/AC-100/6 - Rudder Mass Balance - Modification","slug":"ad-ac-100-6-rudder-mass-balance-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41405,"registerId":"commonwealth-F2006B02175-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC-100/6 - Rudder Mass Balance - Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 8/1968,Aircraft below 5700 kg,S.L. Industries Commander 100 Series and Volair 10 Series Aeroplanes,Rudder Mass Balance - Modification,6\ntitle: Airworthiness Directive - AD/AC-100/6 - Rudder Mass Balance - Modification\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)  S.L. Industries Commander 100 Series and Volair 10 Series Aeroplanes\n\n \n\nAD/AC-100/6 Rudder Mass Balance - Modification 8/68\n\nApplicability: All models with S/Nos. 026 to 078. Document:  Aero Commander Model 100 SB 1005. Compliance:               Forthwith.\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, targeted safety directive. Airworthiness Directives are inherently narrow in scope — they address specific technical defects in specific aircraft types. There is no evidence of scope creep; the document maintains its original purpose of mandating a single safety modification."},"complexity_factors":["Extremely short document (approximately 100 words of substantive content)","No defined terms section — all language is plain operational English","Single, unambiguous applicability criterion (serial number range)","No cross-references to other legislation beyond the enabling regulation (CAR 1998 Part 39)","No conditional logic, exceptions, or alternative compliance methods","Simple command structure: applicability + document reference + compliance deadline"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific light aircraft to modify the rudder (the vertical control surface at the tail that steers the plane left and right).\n\n**What it does:**\n- **Mandates a modification** to the \"rudder mass balance\" — a weight system that prevents dangerous vibrations (flutter) in the rudder during flight.\n- **Applies to:** S.L. Industries Commander 100 Series and Volair 10 Series aeroplanes (small aircraft under 5,700 kg) with serial numbers 026 through 078.\n- **Requires compliance:** \"Forthwith\" — meaning immediately, without delay.\n- **References:** Aero Commander Service Bulletin 1005 (the technical instructions for the fix).\n\n**Why it matters:**\nRudder flutter can cause catastrophic structural failure and loss of control. This AD addresses a known safety defect in these specific aircraft. Owners cannot legally fly these planes until the modification is completed."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"Based on the supplied text, the directive applies specifically to Commander 100 / Volair 10 aeroplanes with serial numbers 026–078 and requires modification per Aero Commander Model 100 SB 1005 with immediate effect. The document provides no indication that the scope has been altered from an earlier or original intent within the excerpt provided."},"complexity_factors":["Narrow applicability: only aircraft with serial numbers 026–078 are affected, which limits scope and stakeholder complexity.","Single technical action referenced (one service bulletin: Aero Commander Model 100 SB 1005) reduces procedural complexity.","Immediate compliance requirement (\"Forthwith\") increases scheduling pressure but does not add legal complexity.","Technical execution requires qualified maintenance personnel and parts, introducing operational complexity (logistics, downtime).","The directive excerpt lacks explanatory material (no stated hazard or enforcement detail), which simplifies legal text but leaves practical implementation questions for operators."],"plain_english_summary":"CASA mandates an immediate modification to the rudder mass balance for S.L. Industries Commander 100 and Volair 10 aeroplanes with serial numbers 026–078, to be carried out per Aero Commander Model 100 SB 1005.  \n\nOwners/operators (and the maintenance organisations who perform the work) must arrange and bear the practical burden of parts, labour and downtime; the directive gives no further funding, rationale or calendar deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-100-6-rudder-mass-balance-modification","history":"/api/acts/ad-ac-100-6-rudder-mass-balance-modification/history","analysis":"/api/acts/ad-ac-100-6-rudder-mass-balance-modification/analysis","conflicts":"/api/acts/ad-ac-100-6-rudder-mass-balance-modification/conflicts","importantCases":"/api/acts/ad-ac-100-6-rudder-mass-balance-modification/important-cases","documents":"/api/acts/ad-ac-100-6-rudder-mass-balance-modification/documents"}}