{"id":"F2006B08496","name":"AD/CF6/7 - First Stage High Pressure Turbine Disc Embossment Radii","slug":"ad-cf6-7-first-stage-high-pressure-turbine-disc-embossment-radii","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51198,"registerId":"commonwealth-F2006B08496-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CF6/7 - First Stage High Pressure Turbine Disc Embossment Radii","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/CF6/7 First Stage High Pressure Turbine Disc Embossment Radii\n\nApplicability: CF6-80A/A2, -80A1/A3 engines.\n\n# 9/86\n\n \n\nRequirement: Inspect first stage high pressure turbine discs in accordance with the requirements of General Electric SB (CF6-80A Series) A72-446.\n\n \n\nReference Document FAA AD 86-15-04 Amdt 39-5353.\n\n \n\nCompliance: In accordance with the Requirement Document.\n\n \n\nBackground:  This Directive has been issued to require inspection of certain first stage turbine discs for blemishes in the forward and aft embossment radii. The manufacturer advises blemishes in the embossment radii may affect the service life of the discs.\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 discrete, single-issue airworthiness directive focused specifically on inspection of turbine disc embossment radii. It has not expanded beyond its original safety purpose. The document appears complete and targeted."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (specific engine models)","Single, unambiguous requirement (inspect per specified service bulletin)","No nested conditions, exceptions, or alternative compliance methods","No cross-references to other legislation or regulations beyond the cited service bulletin and FAA AD","Straightforward compliance timeline ('in accordance with the Requirement Document')","Technical terminology is specific but limited to a single mechanical component"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft engines.\n\n**What it does:** It requires owners and operators of specific General Electric jet engines (the CF6-80A/A2 and CF6-80A1/A3 models) to inspect a particular engine component — the \"first stage high pressure turbine disc.\" Specifically, they must check for surface defects (called \"blemishes\") in curved sections known as \"embossment radii\" (the rounded edges where the disc meets other parts).\n\n**Who it affects:** Airlines, aircraft maintenance organisations, and any operators using aircraft powered by these specific GE CF6 engines — commonly found on older Boeing 767 and Airbus A300/A310 aircraft.\n\n**Why it matters:** The manufacturer (General Electric) discovered that surface defects in these specific areas could reduce the lifespan of the turbine discs or potentially lead to failure. Since turbine discs spin at extreme speeds and temperatures, a failure could cause catastrophic engine damage or even bring down an aircraft. This directive ensures potential problems are caught before they become dangerous.\n\n**What must be done:** Operators must follow the inspection procedures laid out in General Electric Service Bulletin A72-446. The directive references a US Federal Aviation Administration (FAA) directive (86-15-04) as the source document, meaning Australia is adopting the same safety standard as the United States."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The source text does not indicate any change to the AD’s scope from an earlier version. The document, as presented, sets a clear scope (specified engine models) and a single requirement (inspect first-stage HP turbine discs per GE SB A72-446). No amendment or narrowing/broadening of scope is stated in the provided text."},"complexity_factors":["Narrow technical scope: applies only to specified CF6 engine models (CF6-80A/A2, -80A1/A3) (\"Applicability\").","Action delegated to external technical documents: inspection procedures and acceptance criteria are contained in GE SB A72-446 and an FAA AD rather than in the AD text itself (\"Requirement\"; \"Reference Document\").","Technical expertise required: evaluating embossment radii blemishes and following the Service Bulletin requires specialised maintenance skill and equipment (implied by the Requirement referencing a manufacturer SB).","Operational uncertainty: the AD does not state inspection intervals, grounding conditions, or corrective actions—those are in the referenced documents, so operational impact depends on those external specifications (\"Compliance\"; \"Requirement\").","Regulatory enforcement versus technical specification split: CASA mandates compliance but delegates technical content to manufacturer/FAA material (header; \"Requirement\"; \"Reference Document\")."],"plain_english_summary":"This AD requires owners/operators of specified GE CF6-80A/A2 and CF6-80A1/A3 engines to inspect first-stage high‑pressure turbine discs per GE Service Bulletin A72‑446 (and the referenced FAA AD). It responds to manufacturer reports that blemishes in the embossment radii can shorten disc life, making inspections mandatory and shifting inspection/repair costs and operational impact onto operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-7-first-stage-high-pressure-turbine-disc-embossment-radii","history":"/api/acts/ad-cf6-7-first-stage-high-pressure-turbine-disc-embossment-radii/history","analysis":"/api/acts/ad-cf6-7-first-stage-high-pressure-turbine-disc-embossment-radii/analysis","conflicts":"/api/acts/ad-cf6-7-first-stage-high-pressure-turbine-disc-embossment-radii/conflicts","importantCases":"/api/acts/ad-cf6-7-first-stage-high-pressure-turbine-disc-embossment-radii/important-cases","documents":"/api/acts/ad-cf6-7-first-stage-high-pressure-turbine-disc-embossment-radii/documents"}}