{"id":"F2006B08476","name":"AD/CF6/33 - HPT Stage 2 Disk Life Limits","slug":"ad-cf6-33-hpt-stage-2-disk-life-limits","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51147,"registerId":"commonwealth-F2006B08476-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CF6/33 - HPT Stage 2 Disk Life Limits","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\nAD/CF6/33 HPT Stage 2 Disk Life Limits 11/95\n\nApplicability: CF6-50/-45 series.\n\n \n\nRequirement: Action in accordance with the technical requirements of FAA AD 95-08-03.\n\n \n\nNote: Refer to GE SB 72-1069.\n\n \n\nCompliance: As specified in the Requirement Document.\n\n \n\nBackground:  This AD is issued to reflect the manufacturer’s requirement to reduce the certified life of the HPT Stage 2 disk.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope: imposing a specific life limit on one engine component. It has not expanded beyond this safety-critical maintenance requirement."},"complexity_factors":["Extremely short document — only 8 substantive lines","No defined terms section; all terminology is standard aviation shorthand","Single operative requirement: 'do what the FAA says'","No conditional logic, exceptions, or nested provisions","Cross-references only to external documents (FAA AD and GE Service Bulletin), not to other legislation"],"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). Think of it like a recall notice for aircraft parts, but legally binding.\n\n**What it does:** It forces airlines and aircraft operators to reduce the permitted lifespan of a specific jet engine component — the **High Pressure Turbine (HPT) Stage 2 disk** in General Electric CF6-50 and CF6-45 engines.\n\n**Why it matters:** The manufacturer (General Electric) discovered this disk wears out faster than originally certified. Flying with an expired disk risks catastrophic engine failure. This AD ensures Australian operators follow the same safety fix as the US Federal Aviation Administration (FAA).\n\n**Who must act:** Anyone operating aircraft with CF6-50 or CF6-45 series engines — typically older Boeing 747s, DC-10s, and Airbus A300s.\n\n**What operators must do:** Follow the technical instructions in **FAA AD 95-08-03** (the American safety order) and consult **GE Service Bulletin 72-1069** for the new, shorter life limits and inspection procedures."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument does not expand the range of affected parts or add new categories of obligation; it implements a change in the certified life for the existing HPT Stage 2 disk on CF6-50 and CF6-45 engines and requires operators to follow the technical requirements of FAA AD 95-08-03. The Background explicitly states the AD is issued to reflect the manufacturer’s requirement to reduce the certified life, which indicates the AD’s scope aligns with that stated purpose (Background; Requirement; Applicability)."},"complexity_factors":["Dependence on external technical documents (FAA AD 95-08-03 and GE SB 72-1069) requiring operators to obtain and interpret those sources (Requirement; Note).","Requirement to change maintenance life-tracking and scheduling processes to a new certified life limit (Background; Compliance).","Technical subject-matter (HPT Stage 2 disk life limits) requiring specialised engineering/maintenance interpretation rather than simple administrative action (Background; Note).","Narrow applicability (only CF6-50/-45 series) but significant impact for affected operators, requiring asset-level compliance checks (Applicability).","Limited on-face discretion: the AD mandates following the referenced FAA AD, so alternative compliance generally requires regulator-approved deviations (Requirement)."],"plain_english_summary":"This instrument shortens the certified service life for the High-Pressure Turbine Stage 2 disk on GE CF6-50 and CF6-45 engines and makes compliance mandatory by requiring operators to follow FAA Airworthiness Directive 95-08-03 (with technical detail in GE SB 72-1069).  \n\nIt affects operators, owners and maintenance organisations, forcing earlier inspections/overhauls or replacements and shifting direct maintenance costs, scheduling and record-keeping responsibilities onto them."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-33-hpt-stage-2-disk-life-limits","history":"/api/acts/ad-cf6-33-hpt-stage-2-disk-life-limits/history","analysis":"/api/acts/ad-cf6-33-hpt-stage-2-disk-life-limits/analysis","conflicts":"/api/acts/ad-cf6-33-hpt-stage-2-disk-life-limits/conflicts","importantCases":"/api/acts/ad-cf6-33-hpt-stage-2-disk-life-limits/important-cases","documents":"/api/acts/ad-cf6-33-hpt-stage-2-disk-life-limits/documents"}}