{"id":"F2009L02682","name":"AD/CF6/77 - High Pressure Compressor Rotor","slug":"ad-cf6-77-high-pressure-compressor-rotor","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":79757,"registerId":"commonwealth-F2009L02682-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/CF6/77 | High Pressure Compressor Rotor | 9/2009 DM |\n| --------- | ------------------------------ | --------- |\n\n| Applicability: | General Electric Company (GE) CF6-80C2B5F turbofan engines with a high-pressure compressor rotor (HPCR) stages 11-14 spool/shaft, part number (P/N) 1703M74G03, installed.Note 1: These engines are installed on, but not limited to, Boeing 747 series aeroplanes.                                                                                                                                                                         |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Remove any CF6-80C2B5F turbofan engine that has an HPCR stages 11-14 spool/shaft, P/N 1703M74G03, before the spool/shaft meets or exceeds the new, reduced life cycle limit of 19,500 cycles.2. Do not install any CF6-80C2B5F turbofan engine that has an HPCR stages 11-14 spool/shaft, P/N 1703M74G03, that meets or exceeds 19,500 cycles.Note 2: FAA AD 2009-14-08 dated 25 June 2009 refers.                                       |\n| Compliance:    | From the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                                                                         |\n|                | This Airworthiness Directive becomes effective on 5 August 2009.                                                                                                                                                                                                                                                                                                                                                                            |\n| Background:    | This AD results from an internal GE audit that compared the life limited parts certification documentation to the airworthiness limitations section (ALS) of the instructions for continuing airworthiness (ICA). This AD is intended to prevent HPCR stages 11-14 spool/shaft fatigue cracks caused by exceeding the life limit, which could result in a possible uncontained failure of the HPCR spool/shaft and damage to the aeroplane. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n2 July 2009","sortOrder":0},{"sectionNumber":"AD/CF6/77","sectionType":"part","heading":"AD/CF6/77","content":"## AD/CF6/77","sortOrder":1},{"sectionNumber":"High Pressure Compressor Rotor","sectionType":"part","heading":"High Pressure Compressor Rotor","content":"## High Pressure Compressor Rotor","sortOrder":2},{"sectionNumber":"9/2009 DM","sectionType":"part","heading":"9/2009 DM","content":"## 9/2009 DM","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific safety-critical component. It has not expanded beyond its original purpose of mandating retirement of a specific life-limited part."},"complexity_factors":["Single, clearly defined applicability (one specific engine model and part number)","Two straightforward compliance requirements (remove before limit, don't install if over limit)","Single numeric threshold (19,500 cycles) with no conditional logic or exceptions","No cross-references to other legislation (only a non-binding reference to the corresponding FAA directive)","No defined terms section — technical terms are either self-explanatory or standard aviation terminology","Short document (approximately 200 words of substantive content)"],"plain_english_summary":"This airworthiness directive requires operators to remove and prohibit installation of General Electric CF6-80C2B5F engines that contain the high‑pressure compressor rotor stages 11–14 spool/shaft once that part reaches 19,500 flight cycles. It affects airlines and maintenance organisations (notably Boeing 747 operators) because GE found published life‑limits didn’t match maintenance manuals, raising risk of fatigue cracks and possible uncontained engine failure if the part is flown beyond the limit."},"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The AD narrows the permissible life of the HPCR stages 11–14 spool/shaft by imposing a reduced life limit of 19,500 cycles and mandates removal and prohibition on installing units at or above that threshold (Requirement: remove before 19,500 cycles; do not install at/above 19,500). The change originates from a GE audit that identified mismatches between life‑limited parts certification and the ALS/ICA (Background), so the AD modifies operational lifecycle scope for affected parts."},"complexity_factors":["Narrow technical applicability to a single engine model and specific part number (Applicability).","A single, prescriptive life‑limit threshold (19,500 cycles) that triggers mandatory removal and installation prohibition (Requirement).","Immediate compliance obligation from the AD effective date, creating short lead time for operational planning (Compliance: effective 5 August 2009).","Operational tracking burden: operators must monitor individual spool/shaft cycle counts and schedule removals before the limit (Requirement/Applicability).","Cross‑reference to FAA AD 2009‑14‑08 adds interjurisdictional alignment and traceability (Requirement, Note 2).","Origin in an internal GE audit comparing certification paperwork to ALS/ICA, which changes the certified life limits (Background).","Potential logistical and replacement costs for operators who must remove/replace engines sooner than previously planned (implicit from Requirement/Background)."],"plain_english_summary":"This Airworthiness Directive requires operators to remove GE CF6-80C2B5F engines fitted with the high‑pressure compressor rotor (HPCR) stages 11–14 spool/shaft P/N 1703M74G03 before that shaft reaches 19,500 cycles, and forbids installing any such engine that has accumulated 19,500 cycles or more. It takes effect 5 August 2009. The measure follows a GE audit that found a mismatch in life‑limit documentation and aims to prevent fatigue cracks and possible uncontained spool/shaft failure; it affects operators of aircraft using these engines (eg, some Boeing 747s)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-77-high-pressure-compressor-rotor","history":"/api/acts/ad-cf6-77-high-pressure-compressor-rotor/history","analysis":"/api/acts/ad-cf6-77-high-pressure-compressor-rotor/analysis","conflicts":"/api/acts/ad-cf6-77-high-pressure-compressor-rotor/conflicts","importantCases":"/api/acts/ad-cf6-77-high-pressure-compressor-rotor/important-cases","documents":"/api/acts/ad-cf6-77-high-pressure-compressor-rotor/documents"}}