{"id":"F2006B08993","name":"AD/DHC-1/1 - Tailplane Bracket Bolt - Locking","slug":"ad-dhc-1-1-tailplane-bracket-bolt-locking","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52628,"registerId":"commonwealth-F2006B08993-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-1/1 - Tailplane Bracket Bolt - Locking","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)  De Havilland DHC-1 (Chipmunk) Series Aeroplanes\n\n \n\nAD/DHC-1/1 Tailplane Bracket Bolt - Locking 11/50\n\nApplicability: All models.\n\n \n\nDocument: 1. DH TNS Series CTR No. 135; or\n\n \n\n2. Air Ministry Modification Chipmunk No. H.47; or 3. ANO 104.1.14.15.5.1.\n\nCompliance: 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\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1340},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow technical scope regarding tailplane bracket bolt locking on DHC-1 aircraft. No expansion of applicability or additional requirements have been added."},"complexity_factors":["Single unambiguous compliance requirement","No defined terms or interpretation section","No conditional provisions or exceptions","Immediate compliance with no phased implementation","Minimal cross-references limited to three technical source documents"],"plain_english_summary":"**What this is:** An airworthiness directive — a compulsory safety order issued by the Civil Aviation Safety Authority.\n\n**What it does:** Requires immediate action (\"forthwith\") to fix the locking mechanism on the tailplane bracket bolt for De Havilland DHC-1 Chipmunk aircraft. Operators must follow one of three specified technical documents to ensure the bolt is properly secured.\n\n**Who it affects:** Anyone who owns or operates any model of the De Havilland DHC-1 (Chipmunk) aeroplane in Australia.\n\n**Why it matters:** The tailplane is the horizontal wing at the back of the aircraft that controls pitch. A faulty bracket bolt could lead to structural failure or loss of control. This directive mandates a specific safety modification to prevent accidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-1-1-tailplane-bracket-bolt-locking","history":"/api/acts/ad-dhc-1-1-tailplane-bracket-bolt-locking/history","analysis":"/api/acts/ad-dhc-1-1-tailplane-bracket-bolt-locking/analysis","conflicts":"/api/acts/ad-dhc-1-1-tailplane-bracket-bolt-locking/conflicts","importantCases":"/api/acts/ad-dhc-1-1-tailplane-bracket-bolt-locking/important-cases","documents":"/api/acts/ad-dhc-1-1-tailplane-bracket-bolt-locking/documents"}}