{"id":"F2006B02736","name":"AD/B727/35 - Fuel Lines Within Fuselage - Modification","slug":"ad-b727-35-fuel-lines-within-fuselage-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42078,"registerId":"commonwealth-F2006B02736-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/35 - Fuel Lines Within Fuselage - 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)  Boeing 727 Series Aeroplanes\n\n \n\nAD/B727/35 Fuel Lines Within Fuselage - Modification 11/66\n\nApplicability: All models. Document: Boeing SB No. 28-26. Compliance: 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 \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The supplied text is a single AD that mandates modification of fuel lines within the fuselage for all Boeing 727 models, referencing Boeing SB No. 28-26 and requiring immediate compliance. The text does not indicate a change from any prior instrument or original intent; there is no information in the supplied material showing scope expansion or narrowing compared with a previous version."},"complexity_factors":["Single mandatory action (modification of fuel lines) with a clear applicability (all Boeing 727 models) reduces procedural complexity (\"Applicability: All models\").","Immediate compliance requirement (\"Compliance: Forthwith\") increases operational pressure and reduces scheduling flexibility.","Technical details and methods are not included in the AD and are delegated to an external document (Boeing SB No. 28-26), requiring operators to consult that bulletin for execution.","No rationale, cost estimate, or phased compliance plan is provided in the supplied text, which increases informational uncertainty for planning.","Enforcement mechanism is standard (Part 39 Airworthiness Directive), so legal execution is straightforward but depends on regulator oversight."],"plain_english_summary":"This Airworthiness Directive (Part 39) mandates immediate modification of in‑fuselage fuel lines on all Boeing 727 aeroplanes, to be carried out per Boeing Service Bulletin No. 28‑26. Compliance is compulsory \"forthwith\" and enforced by CASA.\n\nThe practical burden—parts, labour and any downtime—falls on aircraft owners/operators; technical details and procedures are contained in the referenced Boeing service bulletin."},"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive from 1966 (indicated by \"11/66\" — November 1966). It has not expanded beyond its original narrow purpose of addressing a specific fuel line modification on one aircraft type. Airworthiness Directives are inherently limited in scope by design."},"complexity_factors":["Extremely short document — only 4 substantive lines of regulatory text","Zero defined terms in the directive itself (relies entirely on external Boeing document)","No conditional logic, exceptions, or nested provisions","No cross-references to other legislation beyond the enabling regulation (CAR 1998 Part 39)","Simple command structure: applicability + document reference + compliance deadline","Single, unambiguous compliance action required"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires aircraft owners or operators to fix a specific safety problem.\n\n**What it does:** It orders modifications to **fuel lines inside the fuselage** (the main body of the aircraft) on all **Boeing 727 series aeroplanes**.\n\n**Who it affects:** Anyone who owns or operates a Boeing 727 in Australia — all models are covered.\n\n**What must be done:** Operators must follow **Boeing Service Bulletin No. 28-26** — a technical instruction manual from the manufacturer detailing exactly how to modify the fuel lines.\n\n**When:** **\"Forthwith\"** — meaning immediately, without delay. This is urgent.\n\n**Why it matters:** Fuel lines inside the fuselage pose a serious fire or explosion risk if they leak or fail. This directive likely addresses a known defect or safety concern that requires immediate correction to keep passengers and crew safe."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-35-fuel-lines-within-fuselage-modification","history":"/api/acts/ad-b727-35-fuel-lines-within-fuselage-modification/history","analysis":"/api/acts/ad-b727-35-fuel-lines-within-fuselage-modification/analysis","conflicts":"/api/acts/ad-b727-35-fuel-lines-within-fuselage-modification/conflicts","importantCases":"/api/acts/ad-b727-35-fuel-lines-within-fuselage-modification/important-cases","documents":"/api/acts/ad-b727-35-fuel-lines-within-fuselage-modification/documents"}}