{"id":"F2011L02514","name":"AD/CF6/74 Amdt 1 - High Pressure Compressor Spool Shaft Stage 14 Disc","slug":"ad-cf6-74-amdt-1-high-pressure-compressor-spool-shaft-stage-14-disc","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":88283,"registerId":"commonwealth-F2011L02514-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/CF6/74 Amdt 1 | High Pressure CompressorSpool Shaft Stage 14 Disc | 24/2011 |\n| ---------------- | ------------------------------------------------- | ------- |\n\n| Applicability: | General Electric Company (GE) CF6-80C2 and CF6-80E1 series turbofan engines with high-pressure compressor rotor (HPCR) spool shaft stage 14 disks, part number (P/N) 1703M49G02, 1703M49G03, or 1509M71G10 installed.Note 1: These engines are installed on, but not limited to, Airbus A300-600R/F, A310-200/300, and A330-200/300, and Boeing 747-200B/300/400/400D/400F,767-200/300/400F/400ER, and MD-11 aeroplanes.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Using the following Alert Service Bulletin (ASB) instructions, perform a one-time ECI of the HPCR spool shaft stage 14 disk web for crack indications, and remove from service those parts found to be cracked.Use paragraphs 3.B.(1) through 3.B.(5) of the Accomplishment Instructions of GE ASB No. CF6-80C2 S/B 72-A1122, Revision 1, dated 19 June 2006, to ECI theCF6-80C2 series engine HPCR spool shaft stage 14 disk web at the module level.Use paragraph 3.C.(1) of the Accomplishment Instructions of GE ASB No.CF6-80C2 S/B 72-A1122, Revision 1, dated 19 June 2006, to ECI the CF6-80C2 series engine HPCR spool shaft stage 14 disk web at the piece-part level.Use paragraphs 3.B.(1) through 3.B.(5) of the Accomplishment Instructions of GE ASB No. CF6-80E1 S/B 72-A0258, Revision 1, dated 15 June 2006, to ECI theCF6-80E1 series engine HPCR spool shaft stage 14 disk web at the module level.Use paragraph 3.C.(1) of the Accomplishment Instructions of GE ASB No. CF6-80E1 S/B 72-A0258, Revision 1, dated 15 June 2006, to ECI the HPCR spool shaft stage 14 disk web at the piece-part level.Previous CreditPerformance of a one-time ECI of the HPCR spool shaft stage 14 disk web for crack indications, using the procedures defined in the following service documents before the original effective date of this AD, satisfies the compliance requirements specified in this AD: |\n\n|             | a) GE ASB No. CF6 80C2 S/B 72-A1122, dated 19 January 2004, forCF6-80C2 series engines.b) GE ASB No. CF6 80E1 S/B 72-A0258, dated 19 January 2004, for CF6-80E1 series engines.Later revisions to GE ASB No. CF6-80C2 S/B 72-A1122, Revision 1, dated 19 June 2006 or GE ASB No. CF6-80E1 S/B 72-A0258, Revision 1, dated 15 June 2006, approved by the United States Federal Aviation Administration (FAA) as an Alternative Method of Compliance (AMOC) to FAA 2009-07-03 Amdt 39-15862, are considered acceptable for compliance with the equivalent Requirements of this AD.                                                                                                                      |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | Note 2: FAA AD 2009-07-03 Amdt 39-15862 dated 18 March 2009 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n| Compliance: | At the next engine shop visit where the separation of a major engine flange will occur after the effective date of this AD, unless the actions have already been done.For the purpose of this AD, introduction of an engine into a shop solely for the following maintenance actions is not considered an engine shop visit:(1) Removal of a compressor case for airfoil or variable stator vane bushing maintenance.(2) Removal or replacement of the stage 1 fan disk.(3) Replacement of the turbine rear frame.(4) Removal or replacement of the accessory and/or transfer gearbox.(5) Removal or replacement of the fan forward case.(6) Any combination of the maintenance actions listed above. |\n|             | This Amendment becomes effective on 1 December 2011.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| Background: | This AD results from reports of 12 cracked HPCR spool shaft stage 14 disk webs discovered to date. The issuing of this AD is intended to prevent cracks from propagating to an uncontained failure of the disk and damage to the aeroplane.Amendment 1 notates the acceptability of an FAA Approved AMOC for compliance with the equivalent requirements of this AD.                                                                                                                                                                                                                                                                                                                                  |\n\n|     | The original issue of this Directive became effective on 4 June 2009. |\n| --- | --------------------------------------------------------------------- |\n\n![](image.001.png)  \nMike Higgins  \nDelegate of the Civil Aviation Safety Authority\n\n29 November 2011","sortOrder":0},{"sectionNumber":"AD/CF6/74 Amdt 1","sectionType":"part","heading":"AD/CF6/74 Amdt 1","content":"## AD/CF6/74 Amdt 1","sortOrder":1},{"sectionNumber":"High Pressure CompressorSpool Shaft Stag","sectionType":"part","heading":"High Pressure CompressorSpool Shaft Stage 14 Disc","content":"## High Pressure Compressor  \nSpool Shaft Stage 14 Disc","sortOrder":2},{"sectionNumber":"24/2011","sectionType":"part","heading":"24/2011","content":"## 24/2011","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing Airworthiness Directive. The amendment is narrow and technical — it adds recognition of FAA-approved Alternative Methods of Compliance (AMOCs) as acceptable for compliance. The core scope (inspecting stage 14 disks for cracks) remains identical to the original 2009 directive. No expansion of affected aircraft, engines, or safety objectives."},"complexity_factors":["Multiple specific part numbers (P/N 1703M49G02, 1703M49G03, 1509M71G10) requiring precise identification","Cross-references to four different GE Alert Service Bulletin documents with specific paragraph citations (3.B.(1) through 3.B.(5), 3.C.(1))","Dual applicability tracks: separate procedures for CF6-80C2 and CF6-80E1 engine series","Two-level inspection requirements: module-level vs piece-part level with different ASB references","Conditional compliance timing: 'next engine shop visit' with six specific exclusions defining what does NOT constitute a shop visit","Previous credit provisions allowing compliance via earlier document revisions","International regulatory cross-reference to FAA AD 2009-07-03 and AMOC acceptance framework","Technical aviation terminology throughout (HPCR, ECI, ASB, turbofan, flange separation)"],"plain_english_summary":"This AD mandates a one‑time eddy‑current inspection of the stage‑14 high‑pressure compressor rotor disk on GE CF6‑80C2 and CF6‑80E1 engines at the next engine shop visit after 1 Dec 2011, removing any cracked disks from service. It affects airlines, AMOs, owners and lessors of affected wide‑body aircraft and matters because cracked disks risk uncontained failure. Amendment 1 accepts FAA‑equivalent inspections to reduce duplication."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"Amendment 1 does not expand the set of engines or parts subject to inspection, nor does it add recurring inspection requirements or new mandatory actions. The amendment records that FAA‑approved Alternative Methods of Compliance (AMOCs) for later ASB revisions are acceptable for compliance with the equivalent requirements of this AD (see Previous Credit / Note 2). That annotation provides limited procedural flexibility but does not materially broaden the AD’s substantive scope or purpose, which remains a one‑time inspection to detect and remove cracked stage 14 disk webs."},"complexity_factors":["Multiple cross‑referenced GE Alert Service Bulletins (CF6‑80C2 S/B 72‑A1122 and CF6‑80E1 S/B 72‑A0258) with different paragraphs for module vs piece‑part level inspections","Exceptions and previous‑credit rules referencing earlier ASB editions (19 Jan 2004) and later FAA‑approved AMOCs","A specific, non‑exhaustive definition of what does and does not count as an \"engine shop visit\" (6 distinct sub‑items creating conditional timing rules)","External cross‑reference to FAA AD 2009‑07‑03 (Note 2) and acceptance of FAA AMOC — introduces interstate regulatory dependency","Single action (one‑time ECI) but with conditional compliance timing tied to maintenance events rather than a fixed calendar deadline","Multiple part numbers specified for applicability (three P/Ns) and multiple engine models listed, increasing the set of potentially affected operators"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires a one-time eddy-current inspection (ECI) of the high‑pressure compressor rotor (HPCR) spool shaft stage 14 disk web on specified General Electric CF6 turbofan engines, and requires removal from service any disk found to be cracked. (See: Requirement.)\n- Specifies the exact GE Alert Service Bulletins (ASBs) and the paragraphs within them to be used to carry out the inspections at either the module level or the piece‑part level for the two engine sub‑families (CF6‑80C2 and CF6‑80E1). (See: Requirement.)\n- Accepts compliance if the same inspection was completed before the AD’s original effective date using the earlier edition of those same GE ASBs (the AD gives previous‑credit for inspections done under the 19 Jan 2004 ASBs). It also notes that later revisions to those ASBs, if approved by the FAA as an Alternative Method of Compliance (AMOC), are acceptable. (See: Previous Credit and Note 2.)\n- Sets the compliance timing: inspections must be done at the next engine shop visit after the effective date where a major engine flange separation occurs, unless already done. The AD gives a specific list of maintenance activities that, if performed alone, do not count as a qualifying ‘‘engine shop visit.’’ (See: Compliance.)\n\n**Who is affected**\n\n- Operators and maintenance organisations that own, operate, or maintain GE CF6‑80C2 and CF6‑80E1 engines fitted with HPCR spool shaft stage 14 disks, part numbers 1703M49G02, 1703M49G03, or 1509M71G10. (See: Applicability.)\n- Maintenance, repair and overhaul (MRO) shops that carry out module‑level or piece‑part level ECIs using the specified GE ASB procedures.\n\n**Why it matters (stated purpose and practical effect)**\n\n- The AD was issued because 12 cracked HPCR spool shaft stage 14 disk webs had been found. The stated aim is to prevent crack propagation to an uncontained disk failure that could damage the aeroplane. (See: Background.)\n\n**Costs, incentives and implementation trade‑offs**\n\n- Who pays: aircraft operators bear the direct costs — inspection labour, possible engine disassembly to reach module or piece part level, and the cost of replacing any cracked disks. MRO providers bear the operational burden of scheduling and delivering the specialised ECI service.\n- Scheduling and productivity: the inspection is timed to the next qualifying shop visit (so many operators will plan the check into an already scheduled overhaul). However, if an engine must be disassembled specifically to reach the inspection level, that raises incremental downtime and cost. The AD clarifies six maintenance actions that do not count as a qualifying shop visit (so operators cannot use minor visits to avoid timing). (See: Compliance.)\n- Technical risk: ECI sensitivity and operator proficiency matter. False negatives risk missing cracks; false positives may cause unnecessary removals and replacements. The AD relies on ASB procedures (module vs piece‑part) which define how deep the inspection must go. (See: Requirement.)\n- Supply & replacement risk: if inspections reveal multiple cracked disks across operators, demand for replacement parts and shop capacity could cause short‑term supply or scheduling pressures.\n- Regulatory flexibility: the AD accepts FAA‑approved AMOCs and earlier ASB compliance as satisfying the requirement, which gives operators some pathway to alternative approved procedures. (See: Previous Credit; Note 2.)\n\n**Effects on private choices and markets**\n\n- Maintenance practice: operators must allocate shop visits and MRO capacity for a one‑time inspection. This is a compliance cost that may influence timing of other maintenance or replacement decisions.\n- Competition & service providers: MROs capable of performing the specific ECI may see demand, so there is a modest concentrated benefit for those providers. There is no change to ownership, operation rights, or contractual freedom beyond imposing a technical compliance requirement.\n\n**Implementation & compliance burden (practical points)**\n\n- The AD instructs use of specific GE ASB paragraphs for module or piece‑part level ECI; following these published procedures is necessary to be compliant. (See: Requirement.)\n- The AD gives credit for earlier inspections done using the January 2004 ASBs and allows FAA‑approved later ASB revisions as acceptable. This reduces redundant work for operators who already complied under those documents. (See: Previous Credit; Note 2.)\n\n**Net takeaway**\n\n- This is a targeted, one‑time safety inspection requirement for a defined set of GE CF6 engines and part numbers. The principal impacts are on operators’ maintenance scheduling, MRO workload and potential replacement part costs if cracks are found. The AD provides limited flexibility through acceptance of prior compliant inspections and FAA‑approved AMOCs."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-74-amdt-1-high-pressure-compressor-spool-shaft-stage-14-disc","history":"/api/acts/ad-cf6-74-amdt-1-high-pressure-compressor-spool-shaft-stage-14-disc/history","analysis":"/api/acts/ad-cf6-74-amdt-1-high-pressure-compressor-spool-shaft-stage-14-disc/analysis","conflicts":"/api/acts/ad-cf6-74-amdt-1-high-pressure-compressor-spool-shaft-stage-14-disc/conflicts","importantCases":"/api/acts/ad-cf6-74-amdt-1-high-pressure-compressor-spool-shaft-stage-14-disc/important-cases","documents":"/api/acts/ad-cf6-74-amdt-1-high-pressure-compressor-spool-shaft-stage-14-disc/documents"}}