{"id":"F2006L03204","name":"AD/CF6/62 - High Pressure Turbine Disc","slug":"ad-cf6-62-high-pressure-turbine-disc","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":60520,"registerId":"commonwealth-F2006L03204-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"General Electric Turbine Engines - CF6 S","sectionType":"division","heading":"General Electric Turbine Engines - CF6 Series","content":"### General Electric Turbine Engines - CF6 Series\n\n| AD/CF6/62 | High Pressure Turbine Disc | 11/2006 |\n| --------- | -------------------------- | ------- |\n\n| Applicability: | General Electric Company (GE) CF6-80 model turbine engines as specified in FAA AD 2006-16-06. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement: | Action per the technical requirements of FAA AD 2006-16-06.Note 1: FAA AD 2006-16-06, Amdt 39-14706 refers.Note 2: This directive supersedes CASA AD/CF6/54 (FAA AD 2004-04-07). |\n| Compliance: | As specified in the requirement document with an effective of 26 October 2006. |\n| | This Airworthiness Directive becomes effective on 26 October 2006. |\n| Background: | The AD is superseding an existing airworthiness directive (AD) for GE CF6-80 series turbofan engines with certain stage 1 high- pressure turbine (HPT) rotor disks. That AD currently requires an initial inspection as a qualification for the mandatory rework procedures for certain disks, and repetitive inspections only for certain disks for which the rework procedures were not required. That action also requires reworking certain disks before further flight, and removes certain CF6-80E1 series disks from service. This AD requires the same actions but shortens the compliance schedule for HPT disks that have not been previously inspected using AD/CF6/54 (FAA AD2004-04-07), which this AD supersedes. This AD results from a recent report of an uncontained failure of a stage 1 HPT disk. The issuing of this AD is to detect and prevent cracks in the bottoms of the dovetail slots that could propagate to failure of the disk and cause an uncontained engine failure. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n13 September 2006","sortOrder":0},{"sectionNumber":"AD/CF6/62","sectionType":"part","heading":"AD/CF6/62","content":"## AD/CF6/62","sortOrder":1},{"sectionNumber":"High Pressure Turbine Disc","sectionType":"part","heading":"High Pressure Turbine Disc","content":"## High Pressure Turbine Disc","sortOrder":2},{"sectionNumber":"11/2006","sectionType":"part","heading":"11/2006","content":"## 11/2006","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope — addressing a specific safety defect in specific engine models. It supersedes a previous directive on the same issue but does not expand beyond the original purpose of preventing HPT disk failures."},"complexity_factors":["Short, single-purpose directive (approximately 300 words of substantive text)","Only 2 defined/referenced external documents (FAA AD 2006-16-06 and the superseded CASA AD/CF6/54)","Simple conditional structure: applies to specific engine model series, with compliance actions delegated to the referenced FAA document","No nested exceptions or complex definitional sections","Technical aviation terminology requires domain knowledge but the legal structure is straightforward"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspections and, if needed, rework or replacement (including removal from service of certain CF6-80E1 discs) of stage‑1 high‑pressure turbine rotor discs in GE CF6‑80 engines used on wide‑body aircraft. It affects airlines, operators and maintenance organisations servicing these engines.\n\nIssued after an uncontained engine failure caused by dovetail‑slot cracking, the AD shortens compliance deadlines from the previous directive to prevent catastrophic disc separation."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This AD tightens the compliance schedule for certain CF6‑80 stage‑1 high‑pressure turbine disks compared with the earlier CASA AD/CF6/54 (FAA AD 2004-04-07) it supersedes. Mechanically it retains the same types of actions (initial inspection, mandatory rework for some disks, repetitive inspections for others, and removal of specified disks) but increases near‑term urgency for disks that were not previously inspected. The change is therefore an acceleration (shortening of deadlines) rather than a substantive broadening of the class of equipment regulated."},"complexity_factors":["Direct cross-reference to FAA AD 2006-16-06 for all technical requirements (defers technical detail outside the instrument)","Supersedes a prior AD (AD/CF6/54), introducing a changed compliance timetable","Differentiated compliance timing depending on whether disks were previously inspected under the prior AD (nested conditionality)","Safety‑critical engineering specifics (crack detection, rework criteria) are technical and require specialist interpretation, though not spelled out in the CASA text","Short effective timeline (effective date specified) increasing implementation pressure"],"plain_english_summary":"**What this directive does (mechanically)**\n\n- Applies to General Electric CF6-80 series turbofan engines as specified in the referenced FAA airworthiness directive (FAA AD 2006-16-06). (See \"Applicability\".)\n- Requires operators to carry out the inspections, rework, removals and repetitive checks described in FAA AD 2006-16-06. CASA has adopted the FAA technical requirements rather than restating them. (See \"Requirement\" and \"Compliance\".)\n- Supersedes the earlier CASA directive AD/CF6/54 (which implemented FAA AD 2004-04-07) and shortens the compliance schedule for high-pressure turbine (HPT) stage‑1 disks that have not been previously inspected under the earlier AD. (See \"Requirement\" and \"Background\".)\n- Becomes effective 26 October 2006. (See \"Compliance\".)\n\n**Who is affected**\n\n- Aircraft operators and maintenance organisations that own or maintain aircraft fitted with GE CF6-80 series engines as identified in FAA AD 2006-16-06. (See \"Applicability\".)\n- Maintenance, repair and overhaul (MRO) providers that perform the required inspections and rework.\n\n**Why it matters (stated purpose and technical trigger)**\n\n- CASA states the immediate reason for the directive is a recent report of an uncontained failure of a stage‑1 HPT disk. The directive aims to detect and prevent cracks in the bottoms of dovetail slots of those disks that could grow and cause an uncontained engine failure. (See \"Background\".)\n\n**Practical effects, costs and incentives**\n\n- Operators must schedule and pay for the inspections and any mandatory rework or disk removals described in the FAA AD. Those actions can cause aircraft downtime and maintenance costs and may require replacement parts or engine shop time.\n- The directive shortens the deadline for previously uninspected disks, which concentrates near‑term inspection and repair demand into an earlier window. That increases short‑term costs, labour and MRO capacity requirements compared with the prior AD. (See \"Requirement\" and \"Background\".)\n- The technical requirements and inspection intervals are set by the FAA AD referenced; CASA enforces compliance. Operators have limited discretion except to comply, defer by approved means, or, in practice, to ground/withdraw aircraft if compliance can’t be met. (See \"Requirement\" and \"Compliance\".)\n\n**Implementation risks and trade‑offs**\n\n- Shortened compliance windows can create bottlenecks for MRO shops and parts supplies, increasing aircraft off‑wing time and scheduling complexity.\n- There is an opportunity cost where aircraft may be taken out of service for inspections/rework, reducing capacity for operators.\n- The directive imposes direct costs on operators and MROs; the safety benefit (reduced risk of uncontained failure) is the concentrated benefit identified in the background statement.\n\n**Who pays, who decides, and what behaviour changes**\n\n- Who pays: aircraft operators (and ultimately their customers) pay for inspections, rework and any replacement parts or extra engine shop labour. MROs absorb the operational burden of carrying out the work.\n- Who decides: CASA adopts and enforces the AD; the technical steps to comply are those specified in FAA AD 2006-16-06. Operators decide scheduling and which approved facilities perform the work, subject to the compliance deadlines.\n- Behaviour changes: operators must inspect (and where required rework or remove) affected HPT disks within the specified deadlines; maintenance providers must carry out and document the required actions.\n\n**Source limitations**\n\n- This CASA directive implements and refers to FAA AD 2006-16-06 for the technical details; readers must consult that FAA AD to see the exact inspection methods, thresholds, repetitive intervals and rework instructions. (See \"Requirement\".)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-62-high-pressure-turbine-disc","history":"/api/acts/ad-cf6-62-high-pressure-turbine-disc/history","analysis":"/api/acts/ad-cf6-62-high-pressure-turbine-disc/analysis","conflicts":"/api/acts/ad-cf6-62-high-pressure-turbine-disc/conflicts","importantCases":"/api/acts/ad-cf6-62-high-pressure-turbine-disc/important-cases","documents":"/api/acts/ad-cf6-62-high-pressure-turbine-disc/documents"}}