{"id":"F2006B02116","name":"AD/AC/57 - Pre-Certification Requirements - Modifications","slug":"ad-ac-57-pre-certification-requirements-modifications","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41346,"registerId":"commonwealth-F2006B02116-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/57 - Pre-Certification Requirements - Modifications","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 2/1975,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Pre-Certification Requirements - Modifications,57\ntitle: Airworthiness Directive - AD/AC/57 - Pre-Certification Requirements - Modifications\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/57 Pre-Certification Requirements - Modifications 2/75\n\nApplicability: All models 690 and 690A.\n\n \n\nRequirement: Modify the aircraft in accordance with the requirements of ANO 101.22 in respect of the following:\n\n \n\n1. Install fuelling equipment bonding points at each fuel filling point.\n\n\n \n\n2.        Install and identify external earthing points, for the attachment of ground connections, on each main undercarriage assembly or on the nose gear.\n\n \n\nCompliance: Before 31 March 1975.\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":2823},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive remains tightly focused on its original purpose: requiring specific fuel-system safety modifications (bonding and earthing points) for Twin Commander 690/690A aircraft. There is no evidence of expansion into unrelated operational areas or aircraft types."},"complexity_factors":["Zero defined terms or interpretation section","Only two specific technical requirements enumerated","No conditional logic, exceptions, or alternative compliance methods","Single cross-reference to external technical standard (ANO 101.22)","Document length is under 150 words with clear structure"],"plain_english_summary":"This AD requires Twin Commander 690/690A owners to add bonding points at every fuel fill and external earthing points on the landing gear so static charge from refueling is safely conducted away. \n\nIt affects operators of those models and matters because proper bonding/grounding prevents sparks that could ignite fuel vapors; compliance was required by 31 March 1975."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-57-pre-certification-requirements-modifications","history":"/api/acts/ad-ac-57-pre-certification-requirements-modifications/history","analysis":"/api/acts/ad-ac-57-pre-certification-requirements-modifications/analysis","conflicts":"/api/acts/ad-ac-57-pre-certification-requirements-modifications/conflicts","importantCases":"/api/acts/ad-ac-57-pre-certification-requirements-modifications/important-cases","documents":"/api/acts/ad-ac-57-pre-certification-requirements-modifications/documents"}}