{"id":"F2006B02558","name":"AD/AT/9 Amdt 2 - Control Column Yoke Bolt","slug":"ad-at-9-amdt-2-control-column-yoke-bolt","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41814,"registerId":"commonwealth-F2006B02558-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AT/9 Amdt 2 - Control Column Yoke Bolt","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)  Airtractor AT-300, 400 and 500 Series Aeroplanes\n\n \n\n# AD/AT/9\n\nAmdt 2\n\nApplicability: All models.\n\n# Control Column Yoke Bolt 2/98\n\n \n\nRequirement: Remove the attachment bolt from the control column/aileron torque tube connection and inspect bolt for excessive wear, deformation or cracking.\n\n \n\nNote: Snow Engineering Service Letter #103 refers.\n\n \n\nCompliance: The inspection is to be carried out:\n\n \n\n(a)     Whenever the aircraft has been subjected to heavy wind gusts, jet or rotor blast or any other abnormal loads to the control surfaces whilst the gust locks have not been engaged, and\n\n \n\n(b)     If inspected within the last 12 months in accordance with the previous issue of this Directive then within 12 months of that inspection and thereafter at intervals not exceeding 12 months, or\n\n \n\n(c)     Within 12 months and thereafter at intervals not exceeding 12 months. This amendment becomes effective on 29 January 1998.\n\nBackground: There have been Major Defect Reports of cracking and failure of the bolt. Since the previous amendment was issued, Service Letter #103 has been issued alerting owners to the problem and making available stronger bolts, however the manufacturer still recommends inspection as detailed above. This amendment removes the requirement to carry out a dye penetrant inspection of the bolts and expands the applicability to inspect all control column bolts, irrespective of Part Number.\n\nAmendment 1 of this Airworthiness Directive became effective on 10 August 1989. The original issue of this Airworthiness Directive became effective on\n\n21 November 1988.\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_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment narrows the mandated inspection technique (removes dye‑penetrant requirement) and broadens applicability to require inspection of all control‑column bolts regardless of part number, while keeping recurring inspections and abnormal‑load triggers (Background; Compliance a–c)."},"complexity_factors":["Technical inspection and potential replacement of a primary flight‑control bolt (Requirement).","Multiple compliance triggers and interval rules that must be reconciled (Compliance a–c).","Applicability expanded to all control‑column bolts irrespective of part number, increasing affected parts and aircraft (Background).","Reference to an external Service Letter (#103) for strengthened bolts and parts guidance creates dependency on manufacturer material (Note; Background).","Change in inspection method (removal of dye‑penetrant requirement) alters maintenance procedures and recordkeeping (Background)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Airtractor AT‑300/400/500 series aeroplanes to remove and inspect the control‑column/aileron torque‑tube attachment bolt for excessive wear, deformation or cracking, and to repeat inspections after abnormal loads or at intervals not exceeding 12 months (Requirement; Compliance a–c).\nIt removes the earlier dye‑penetrant test and expands inspection to all control‑column bolts irrespective of part number; operators pay for inspections and any replacements and should consult Snow Engineering Service Letter #103 where relevant (Background; Note)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"The original directive (1988) was narrower in scope, applying only to specific part numbers. Amendment 2 (1998) expanded applicability to 'all control column bolts, irrespective of Part Number' while simultaneously removing the dye penetrant inspection requirement. This represents a scope expansion in coverage (more bolts affected) but a reduction in inspection stringency (removing the dye test). The background indicates the manufacturer now provides stronger bolts, suggesting the safety case shifted from intensive inspection to hardware replacement plus routine inspection."},"complexity_factors":["Single mechanical component focus (one bolt type)","Only 3 compliance triggers (event-based + two alternative time-based schedules)","No defined terms section or interpretation provisions","Minimal cross-referencing (only one service letter mentioned)","Straightforward conditional logic with clear 'or' structure between compliance paths","No penalty provisions, enforcement mechanisms, or appeal processes included","Length: approximately 250 words"],"plain_english_summary":"This rule requires mechanics to remove and inspect the control-column bolt that connects the pilot’s controls to the ailerons on Airtractor AT‑300/400/500 series planes for wear, bends, or cracks. Inspections are required immediately after exposure to strong gusts, jet blast, or rotor wash with unlocked controls, and at 12‑month intervals. It matters because bolt failure can cause loss of aileron control. The revision covers all such bolts (any part number), drops the dye test, and notes stronger replacement bolts exist."}},"importantCases":[],"_links":{"self":"/api/acts/ad-at-9-amdt-2-control-column-yoke-bolt","history":"/api/acts/ad-at-9-amdt-2-control-column-yoke-bolt/history","analysis":"/api/acts/ad-at-9-amdt-2-control-column-yoke-bolt/analysis","conflicts":"/api/acts/ad-at-9-amdt-2-control-column-yoke-bolt/conflicts","importantCases":"/api/acts/ad-at-9-amdt-2-control-column-yoke-bolt/important-cases","documents":"/api/acts/ad-at-9-amdt-2-control-column-yoke-bolt/documents"}}