{"id":"F2006B02069","name":"AD/AC/10 - Fuel Line Routing - Modification","slug":"ad-ac-10-fuel-line-routing-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41299,"registerId":"commonwealth-F2006B02069-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/10 - Fuel Line Routing - 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 NK,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Fuel Line Routing - Modification,10\ntitle: Airworthiness Directive - AD/AC/10 - Fuel Line Routing - 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/10 Fuel Line Routing - Modification NK\n\nApplicability: All models: S/Nos. 231 to 690. Document: 1. Aero Commander SB No. 54; or\n\n2. FAA AD 59-16-1.\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","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The supplied text gives no indication that the scope has been altered from any prior instrument. It applies to Twin Commander series aeroplanes with serial numbers 231–690 and requires modification of fuel line routing by reference to Aero Commander SB No. 54 or FAA AD 59-16-1, to be carried out forthwith. No previous scope or amendment history is included in the supplied document, so there is no basis in the provided text to conclude the directive changes an earlier scope."},"complexity_factors":["Narrow, well-defined applicability by serial number (reduces scope complexity). (Applicability: All models: S/Nos. 231 to 690.)","Mandatory immediate compliance (\"Forthwith\") increases operational urgency and scheduling pressure. (Compliance: Forthwith.)","The directive omits technical detail and delegates implementation to external documents (Aero Commander SB No. 54; FAA AD 59-16-1), requiring users to consult and interpret those sources. (Document references.)","No explanatory rationale or enforcement and verification details are provided in the supplied text, creating interpretation uncertainty for implementers. (Absence of rationale/enforcement text.)","Potential for logistical complexity (parts, skilled labour, downtime) not specified in the directive but implied by the mandatory modification requirement. (Compliance; Document references.)"],"plain_english_summary":"This Airworthiness Directive from CASA requires owners/operators of Twin Commander (Aerocommander/Gulfstream/Rockwell) aeroplanes S/N 231–690 to modify fuel line routing forthwith. Compliance is by following Aero Commander Service Bulletin No. 54 or FAA AD 59‑16‑1. It affects operators, maintenance organisations and technicians, who must schedule downtime, parts and labour (costs typically borne by owners), with technical details and verification to be obtained from the referenced documents."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused specifically on fuel line routing for a narrow subset of aircraft. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 2 defined applicability criteria (aircraft model series and serial number range)","Single compliance requirement with 2 alternative reference documents","No nested conditions, exceptions, or cross-references to other legislation","No interpretation section or defined terms","Binary applicability — either your aircraft is affected or it isn't"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA). An AD is a mandatory safety order — think of it as a \"recall notice\" for aircraft. It requires owners or operators to fix a specific safety problem.\n\n**What it does:** This directive orders modifications to how fuel lines are routed on certain Twin Commander aircraft (specifically the Gulfstream/Rockwell/Aero Commander 500, 600, and 700 series, serial numbers 231 to 690).\n\n**Who it affects:** Anyone who owns or operates these specific Twin Commander aeroplanes with the listed serial numbers.\n\n**What must be done:** The aircraft must be modified \"forthwith\" (immediately) according to either:\n- **Aero Commander Service Bulletin No. 54**, or  \n- **FAA Airworthiness Directive 59-16-1** (the American aviation safety regulator's equivalent order)\n\n**Why it matters:** Fuel line routing is critical — if fuel lines are positioned incorrectly, they can chafe, leak, or fail, creating fire or engine failure risks. This AD likely addresses a known defect where the original routing created a safety hazard. The \"forthwith\" compliance means CASA considered this urgent — no grace period.\n\n**The bottom line:** If you fly or maintain one of these specific Twin Commanders, you cannot legally operate the aircraft until this fuel line modification is completed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-10-fuel-line-routing-modification","history":"/api/acts/ad-ac-10-fuel-line-routing-modification/history","analysis":"/api/acts/ad-ac-10-fuel-line-routing-modification/analysis","conflicts":"/api/acts/ad-ac-10-fuel-line-routing-modification/conflicts","importantCases":"/api/acts/ad-ac-10-fuel-line-routing-modification/important-cases","documents":"/api/acts/ad-ac-10-fuel-line-routing-modification/documents"}}