{"id":"F2006B03027","name":"AD/B747/126 - Pneumatic Duct Coupling","slug":"ad-b747-126-pneumatic-duct-coupling","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42386,"registerId":"commonwealth-F2006B03027-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/126 - Pneumatic Duct Coupling","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 747 Series Aeroplanes\n\n \n\nAD/B747/126 Pneumatic Duct Coupling 9/94\n\nApplicability: All model 747 series aeroplanes with line position 1 through 219 inclusive. Requirement:               Action in accordance with the technical requirements of FAA AD 94-09-13 Amdt 39-\n\n8902.\n\n \n\nNote: Purolator Service Bulletin FSC-912 dated December 1972 refers.\n\n \n\nCompliance: As specified in the Requirement Document.\n\n \n\nBackground: Failures of certain duct couplings installed on the wing leading edge pneumatic duct have been reported.\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":3,"scope_assessment":{"changed":false,"description":"The AD text shows no indication that the scope of affected aircraft or the remedial measures has been altered from the original intent. It applies to all Boeing 747 series aeroplanes with line positions 1–219 and mandates action in accordance with FAA AD 94-09-13 Amdt 39-8902 (Applicability; Requirement). The AD itself does not expand or narrow scope within this text."},"complexity_factors":["Relies on an external FAA AD (FAA AD 94-09-13 Amdt 39-8902) for all technical detail (Requirement).","References an older third-party service bulletin (Purolator FSC-912, Dec 1972) without embedding its content (Note).","Applicability is narrowly drawn (line positions 1–219) but requires operators to determine whether a specific aeroplane is in scope (Applicability).","This AD text does not specify compliance intervals, inspection methods or corrective actions itself — those are in the referenced documents (Requirement; Compliance).","Potential operational impact (inspection/repair downtime and costs) is not quantified here (Requirement; Compliance)."],"plain_english_summary":"This AD requires operators of Boeing 747s with line positions 1–219 to comply with the inspection, modification or replacement actions specified in FAA AD 94-09-13 Amdt 39-8902 (and referenced Purolator service bulletin) after reports of wing leading-edge pneumatic duct coupling failures. Maintenance duty holders must obtain and follow the external FAA document and bear costs, downtime and implementation risks."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific mechanical defect in a specific aircraft series. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 200 words)","Only 1 defined applicability criterion (line positions 1–219)","Single cross-reference to external FAA document (AD 94-09-13)","No nested conditions or exceptions","No interpretation section or defined terms","Background is one sentence explaining the safety issue"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nOrders owners and operators of certain **Boeing 747 aircraft** (specifically those built at production line positions 1 through 219) to inspect and fix a problem with **pneumatic duct couplings** in the wing leading edge.\n\n**The problem:**\nThe couplings (metal connectors that join air ducts) have been failing. These ducts carry hot, pressurised air used for systems like wing anti-icing. If a coupling fails, it could damage the aircraft or cause loss of critical systems.\n\n**What must be done:**\nOperators must follow the technical instructions in **FAA AD 94-09-13** (a matching US safety order). This typically involves inspections, replacements, or modifications to the couplings.\n\n**Who it affects:**\n- Airlines and operators flying early-production Boeing 747s (line numbers 1–219)\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\nAirworthiness Directives are legally binding. Non-compliance can ground an aircraft. This directive prevents potential in-flight failures that could compromise safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-126-pneumatic-duct-coupling","history":"/api/acts/ad-b747-126-pneumatic-duct-coupling/history","analysis":"/api/acts/ad-b747-126-pneumatic-duct-coupling/analysis","conflicts":"/api/acts/ad-b747-126-pneumatic-duct-coupling/conflicts","importantCases":"/api/acts/ad-b747-126-pneumatic-duct-coupling/important-cases","documents":"/api/acts/ad-b747-126-pneumatic-duct-coupling/documents"}}