{"id":"F2006B02133","name":"AD/AC/73 - Wing Fasteners - Modification","slug":"ad-ac-73-wing-fasteners-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41363,"registerId":"commonwealth-F2006B02133-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/73 - Wing Fasteners - 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 7/1981,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Wing Fasteners - Modification,73\ntitle: Airworthiness Directive - AD/AC/73 - Wing Fasteners - 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)  Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes\n\n \n\nAD/AC/73 Wing Fasteners - Modification 7/81\n\nApplicability: All models 690, 690A and 690B with S/Nos. 11001 to 11566 (except 11006). Document:               Gulfstream American (Commander Division) SB No. 182.\n\nCompliance: Within 100 hours time in service after 31 July 1981.\n\n \n\nBackground: Modification is required for increased fastener strength in the engine nacelle area.\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1142},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted, technical safety directive focused exclusively on wing fastener modifications for a specific fleet of Twin Commander aircraft. The scope remains tightly constrained to the original airworthiness safety purpose with no expansion into broader operational or administrative requirements."},"complexity_factors":["Single, clearly defined applicability section targeting specific aircraft serial numbers","Only one compliance action required (follow external Service Bulletin No. 182)","Simple temporal compliance condition (100 hours time in service after fixed date)","No defined terms, cross-references to other legislation, or conditional exceptions"],"plain_english_summary":"This is a **safety order** (called an Airworthiness Directive) issued by Australia's aviation safety regulator (CASA).\n\n**What it does:**\nIt requires owners or operators of specific Twin Commander aircraft models to upgrade the bolts or screws (\"fasteners\") where the wing meets the engine housing.\n\n**Who it affects:**\nOwners of Twin Commander 690, 690A, and 690B aircraft with serial numbers between 11001 and 11566 (but not 11006).\n\n**What must be done:**\nFollow the technical instructions in **Gulfstream American Service Bulletin No. 182** to install stronger fasteners in the engine nacelle area.\n\n**Why it matters:**\nThe original fasteners weren't strong enough, which could create a safety risk. This modification prevents potential structural failures.\n\n**Deadline:**\nThe work must be completed within **100 flight hours** after 31 July 1981."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-73-wing-fasteners-modification","history":"/api/acts/ad-ac-73-wing-fasteners-modification/history","analysis":"/api/acts/ad-ac-73-wing-fasteners-modification/analysis","conflicts":"/api/acts/ad-ac-73-wing-fasteners-modification/conflicts","importantCases":"/api/acts/ad-ac-73-wing-fasteners-modification/important-cases","documents":"/api/acts/ad-ac-73-wing-fasteners-modification/documents"}}