{"id":"F2006B02656","name":"AD/B727/134 - Auxiliary Fuel Tanks","slug":"ad-b727-134-auxiliary-fuel-tanks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41972,"registerId":"commonwealth-F2006B02656-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/134 - Auxiliary Fuel Tanks","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/B727/134 Auxiliary Fuel Tanks 9/91\n\nApplicability: All model 727 aircraft as listed in Boeing SB 727-28-0110.\n\n \n\nRequirement: 1. Inspect aircraft in accordance with Boeing SB 727-28-0110 or CAA approved inspection procedure until modified in accordance with Requirement 2.\n\n \n\n2. Modify aircraft in accordance with Boeing SB 727-28A0067 Revision 1.\n\n \n\nNote: FAA AD 91-09-06 Amdt 39-6977 refers to Boeing SB 727-28A0067 Revision 1.\n\n \n\nCompliance: 1. As specified in the Requirement Document.\n\n \n\n2. Prior to issue of a Certificate of Airworthiness.\n\n \n\nBackground: An uncontrolled fuel leak into the baggage compartment due to damage of an auxiliary fuel tank cell, has occurred.\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":3,"scope_assessment":{"changed":false,"description":"The AD's scope is limited to the model 727 aircraft listed in Boeing SB 727-28-0110 and prescribes inspection until a specified Boeing modification is completed, with the modification required before a Certificate of Airworthiness can be issued (Applicability; Requirement 1; Requirement 2; Compliance 2). The instrument does not indicate any change to that scope from the text provided."},"complexity_factors":["Dependence on external technical documents (Boeing SB 727-28-0110 and Boeing SB 727-28A0067 Revision 1) for procedural detail (Requirement 1; Requirement 2).","Need for CAA approval for alternate inspection procedures introduces regulatory discretion and potential administrative steps (Requirement 1).","Timing constraint tying completion of the modification to issuance of a Certificate of Airworthiness creates an operational constraint for operators (Compliance 2).","Cross-reference to FAA AD requires operators to be aware of related foreign regulatory material, increasing coordination requirements (Note).","Technical subject matter (fuel-tank inspection and modification) requires specialised maintenance capability and parts, adding implementation complexity not detailed in the AD."],"plain_english_summary":"This AD requires owners/operators of affected Boeing 727s to inspect and then modify auxiliary fuel systems per Boeing service bulletins (or a CAA‑approved inspection procedure) to address a risk of fuel leaking into the baggage compartment. It applies to all 727s listed in Boeing SB 727‑28‑0110.\n\nThe modification must be completed before issuance of a Certificate of Airworthiness, so operators bear the inspection, modification and timing costs. The CAA may approve alternate inspection procedures; the AD cross‑references a related FAA AD."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive addressing a specific known defect (auxiliary fuel tank cell damage) in a specific aircraft type. The scope remains tightly focused on its original safety purpose with no evidence of scope creep."},"complexity_factors":["Very short document (under 300 words)","Only 2 substantive requirements with clear sequencing (inspect until modified)","Minimal defined terms (relies on external Boeing service bulletins)","Simple conditional structure: inspect first, then modify","Single cross-reference to FAA AD for informational purposes only","No nested exceptions or complex logical operators"],"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) for specific Boeing 727 aircraft.\n\n**What it does:** It requires owners/operators of all Boeing 727 models listed in Boeing Service Bulletin 727-28-0110 to:\n- **Inspect** their aircraft's auxiliary fuel tanks for damage (following specific Boeing instructions or CASA-approved alternatives) until they complete the permanent fix\n- **Permanently modify** the aircraft by installing a specific fix outlined in Boeing Service Bulletin 727-28A0067 Revision 1\n\n**Who it affects:** Anyone operating Boeing 727 aircraft in Australia that have auxiliary fuel tanks covered by the listed service bulletin.\n\n**Why it matters:** An uncontrolled fuel leak into the baggage compartment has already occurred due to damage to an auxiliary fuel tank cell. This creates serious fire and explosion risks. The directive prevents catastrophic accidents by mandating inspection and repair before the aircraft can be certified as airworthy.\n\n**Key deadlines:**\n- Inspections must follow the timing in the Boeing service bulletin\n- The permanent modification must be completed **before** CASA will issue or renew a Certificate of Airworthiness (the official document allowing an aircraft to fly)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-134-auxiliary-fuel-tanks","history":"/api/acts/ad-b727-134-auxiliary-fuel-tanks/history","analysis":"/api/acts/ad-b727-134-auxiliary-fuel-tanks/analysis","conflicts":"/api/acts/ad-b727-134-auxiliary-fuel-tanks/conflicts","importantCases":"/api/acts/ad-b727-134-auxiliary-fuel-tanks/important-cases","documents":"/api/acts/ad-b727-134-auxiliary-fuel-tanks/documents"}}