{"id":"F2006B09020","name":"AD/DHC-1/4 - Undercarriage Torque Link Centre Hinge Joint - Modification","slug":"ad-dhc-1-4-undercarriage-torque-link-centre-hinge-joint-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52695,"registerId":"commonwealth-F2006B09020-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-1/4 - Undercarriage Torque Link Centre Hinge Joint - Modification","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-1/4 Undercarriage Torque Link Centre Hinge Joint - Modification\n\nApplicability: All English production models. Document: 1. DH Chipmunk Mod. H.92; or\n\n2. ANO 105.1.14.15.5.4.\n\n \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\n\n4/56\n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1321},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope: requiring a specific hardware modification to address a identified safety defect in a particular aircraft type's landing gear assembly."},"complexity_factors":["Single unambiguous operative requirement","No conditional logic or nested exceptions","Universal applicability with no carve-outs","Only two external technical references to consult"],"plain_english_summary":"**What this does:** This directive mandates a safety-critical modification to the landing gear (undercarriage) of specific vintage aircraft. You must modify the centre hinge joint on the torque link—a component that helps the landing gear absorb shock and stay aligned during takeoff and landing.\n\n**Who it affects:** Owners and operators of all English production models of the De Havilland DHC-1 Chipmunk series aeroplanes.\n\n**What you must do:** Carry out the modification exactly as described in either of these technical documents:\n* DH Chipmunk Modification H.92; or\n* Air Navigation Order 105.1.14.15.5.4\n\n**When:** Immediately (the term \"forthwith\" means without delay—there is no compliance grace period).\n\n**Why it matters:** This prevents potential failure of the undercarriage hinge joint, which could cause the landing gear to collapse during takeoff or landing."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-1-4-undercarriage-torque-link-centre-hinge-joint-modification","history":"/api/acts/ad-dhc-1-4-undercarriage-torque-link-centre-hinge-joint-modification/history","analysis":"/api/acts/ad-dhc-1-4-undercarriage-torque-link-centre-hinge-joint-modification/analysis","conflicts":"/api/acts/ad-dhc-1-4-undercarriage-torque-link-centre-hinge-joint-modification/conflicts","importantCases":"/api/acts/ad-dhc-1-4-undercarriage-torque-link-centre-hinge-joint-modification/important-cases","documents":"/api/acts/ad-dhc-1-4-undercarriage-torque-link-centre-hinge-joint-modification/documents"}}