{"id":"F2006B08474","name":"AD/CF6/31 - Fan Stator Case Stiffening Ring and Stage 1 Fan Shroud","slug":"ad-cf6-31-fan-stator-case-stiffening-ring-and-stage-1-fan-shroud","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51141,"registerId":"commonwealth-F2006B08474-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CF6/31 - Fan Stator Case Stiffening Ring and Stage 1 Fan Shroud","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 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  General Electric Turbine Engines - CF6 Series\n\n \n\n# AD/CF6/31 Fan Stator Case Stiffening Ring and Stage 1 Fan Shroud\n\nApplicability: General Electric CF6-45/-50 series engines.\n\n \n\nRequirement: Action in accordance with the technical requirements of FAA AD 94-08-05.\n\n \n\nNote: General Electric CF6-50 Service Bulletin 72-573 refers.\n\n \n\nCompliance: As specified in the FAA AD with an effective date of 18 August 1994.\n\n# 9/94\n\n \n\nBackground: The FAA AD was raised as a result of an uncontained stage one fan blade failure which resulted in an inflight engine shutdown and damage to the aircraft.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific mechanical failure mode in specific engine models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (under 200 words)","No defined terms section — relies entirely on external documents (FAA AD and GE Service Bulletin)","Single, clear applicability criterion (specific engine models)","No conditional logic or nested exceptions within the text itself","Cross-references only to external technical documents, not to other legislative provisions"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order for aircraft engines.\n\n**What it does:**\nOrders owners and operators of specific General Electric jet engines (the CF6-45 and CF6-50 series) to carry out specific safety inspections or repairs. The actual technical work required is set out in an American safety order (FAA AD 94-08-05) and a General Electric service bulletin (SB 72-573).\n\n**Why it exists:**\nA fan blade broke off in flight on one of these engines, causing an \"uncontained failure\" — meaning debris escaped the engine casing. This forced the crew to shut down the engine mid-flight and damaged the aircraft. This directive prevents the same dangerous failure from happening again.\n\n**Who must comply:**\nAnyone operating aircraft with these specific GE CF6 engines in Australia must follow the American FAA directive by the deadline (18 August 1994).\n\n**Why it matters:**\nUncontained engine failures can damage critical aircraft systems, endanger passengers, and even bring down an aircraft. This directive forces operators to fix a known design weakness before it causes another incident."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive adopts and requires compliance with the technical requirements of FAA AD 94-08-05 for General Electric CF6-45/-50 engines and refers to GE Service Bulletin 72-573 (Requirement; Note; Compliance). The instrument does not expand, narrow or otherwise modify the technical scope asserted in the referenced FAA AD within the text provided; it simply imposes that external AD as the applicable requirement in Australia."},"complexity_factors":["Direct cross-reference to an external FAA AD (FAA AD 94-08-05) rather than restating technical measures, requiring users to consult another instrument (Requirement).","Reference to manufacturer service bulletin for technical detail (Note: General Electric CF6-50 Service Bulletin 72-573 refers).","Narrow applicability limited to specific engine models (CF6-45/-50) which reduces breadth but concentrates obligations on a defined group (Applicability).","Legal effect relies on another instrument’s timelines (effective date 18 August 1994) creating dependency on the external document’s structure (Compliance).","Limited text in the directive itself: administrative simplicity in the directive offsets technical complexity located in external documents."],"plain_english_summary":"This directive adopts FAA Airworthiness Directive 94-08-05 (and references GE Service Bulletin 72-573) for General Electric CF6-45 and CF6-50 engines, making the FAA‑specified inspections, repairs or modifications legally mandatory in Australia with effect from 18 August 1994.  \n\nIssued after an uncontained stage‑one fan blade failure, it shifts compliance costs and downtime to engine owners/operators and requires them to follow the FAA/manufacturer technical requirements and timelines."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-31-fan-stator-case-stiffening-ring-and-stage-1-fan-shroud","history":"/api/acts/ad-cf6-31-fan-stator-case-stiffening-ring-and-stage-1-fan-shroud/history","analysis":"/api/acts/ad-cf6-31-fan-stator-case-stiffening-ring-and-stage-1-fan-shroud/analysis","conflicts":"/api/acts/ad-cf6-31-fan-stator-case-stiffening-ring-and-stage-1-fan-shroud/conflicts","importantCases":"/api/acts/ad-cf6-31-fan-stator-case-stiffening-ring-and-stage-1-fan-shroud/important-cases","documents":"/api/acts/ad-cf6-31-fan-stator-case-stiffening-ring-and-stage-1-fan-shroud/documents"}}