{"id":"F2006B02074","name":"AD/AC/15 - Centre Wing - Rear Spar Reinforcement","slug":"ad-ac-15-centre-wing-rear-spar-reinforcement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41304,"registerId":"commonwealth-F2006B02074-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/15 - Centre Wing - Rear Spar Reinforcement","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 NK,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Centre Wing - Rear Spar Reinforcement,15\ntitle: Airworthiness Directive - AD/AC/15 - Centre Wing - Rear Spar Reinforcement\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)  Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes\n\n \n\nAD/AC/15 Centre Wing - Rear Spar Reinforcement NK\n\nApplicability: Models 680E and 720: S/Nos. 242, 501, 623 to 873 except 820, 850, 860, 863, 867\n\nand 872.\n\n \n\nDocument: Aero Commander SB No. 62. 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","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD, as written, sets a specific scope: it applies to Twin Commander models 680E and 720 with the listed serial numbers and mandates compliance with Aero Commander SB No. 62 forthwith. The text contains no indication that the scope has been expanded or reduced from an earlier version; it states applicability, the referenced document, and an immediate compliance requirement. (See: \"Applicability\"; \"Document: Aero Commander SB No. 62\"; \"Compliance: Forthwith\")"},"complexity_factors":["Reference to an external technical document (Aero Commander SB No. 62) that contains the necessary procedural detail","Serial-number-specific applicability requiring operators to check individual aircraft records","Immediate compliance deadline ('Forthwith') that shortens operational flexibility","Sparse content in the AD itself — technical, cost and timing details are absent and must be sought in the SB","Legal enforceability under Civil Aviation Regulations Part 39, creating regulatory consequences for non-compliance"],"plain_english_summary":"This AD requires owners/operators of specified Twin Commander 680E and 720 serial numbers to have the centre wing rear spar reinforced by following Aero Commander Service Bulletin No. 62, with compliance required forthwith. It affects those aircraft, their maintenance organisations, and shifts direct costs (parts, labour, downtime) to operators. The directive is mandatory and enforceable under the Civil Aviation Regulations Part 39."},"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive targeting a specific structural issue on specific aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 100 words of substantive content)","No defined terms section","No cross-references to other legislation (only references a technical service bulletin)","Simple conditional logic: applies to specific serial numbers only","Single compliance requirement with immediate effect","No exceptions, exemptions, or nested conditions"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA). It is a mandatory safety order for specific aircraft.\n\n**What it does:**\nRequires immediate action to reinforce the centre wing rear spar on certain Twin Commander aircraft models.\n\n**Who it affects:**\nOwners and operators of specific Twin Commander 680E and 720 model aeroplanes with particular serial numbers (242, 501, and 623-873, excluding serial numbers 820, 850, 860, 863, 867, and 872).\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. If you own or operate one of these aircraft, you **must** comply with this directive immediately (\"forthwith\") to ensure the aircraft remains safe to fly. The directive references a specific service bulletin (Aero Commander SB No. 62) that contains the technical instructions for the reinforcement work.\n\n**Key points:**\n- **Mandatory:** Non-compliance means the aircraft cannot legally fly\n- **Immediate:** \"Forthwith\" means right away, not at the next scheduled maintenance\n- **Specific:** Only applies to certain serial numbers of the 680E and 720 models"}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-15-centre-wing-rear-spar-reinforcement","history":"/api/acts/ad-ac-15-centre-wing-rear-spar-reinforcement/history","analysis":"/api/acts/ad-ac-15-centre-wing-rear-spar-reinforcement/analysis","conflicts":"/api/acts/ad-ac-15-centre-wing-rear-spar-reinforcement/conflicts","importantCases":"/api/acts/ad-ac-15-centre-wing-rear-spar-reinforcement/important-cases","documents":"/api/acts/ad-ac-15-centre-wing-rear-spar-reinforcement/documents"}}