{"id":"F2012L00820","name":"AD/RB211/43 - Engine - IP Compressor Rotor and IP Turbine Discs","slug":"ad-rb211-43-engine-ip-compressor-rotor-and-ip-turbine-discs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":89135,"registerId":"commonwealth-F2012L00820-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Rolls Royce Turbine Engines - RB211 Seri","sectionType":"division","heading":"Rolls Royce Turbine Engines - RB211 Series","content":"### Rolls Royce Turbine Engines \\- RB211 Series\n\n| AD/RB211/43 | Engine - IP Compressor Rotor and IP Turbine Discs | 7/2012 |\n| ----------- | ------------------------------------------------- | ------ |\n\n| Applicability: | RB211-524 engines installed in Boeing 747, 767 and Lockheed L-1011 aircraft as specified in the requirement document.                                                                                                                                                         |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Withdraw from service any IP compressor rotor drum and IP turbine discs which have been subjected to N2 overspeed as specified in Rolls-Royce Service Bulletin No. 72‑5887 Revision 4 dated September 25, 1998 or later approved revision.Note: UK CAA AD G-009-06-82 refers. |\n| Compliance:    | Following N2 overspeed as specified in the requirement document.                                                                                                                                                                                                              |\n|                | This Airworthiness Directive becomes effective on 30 April 2012.                                                                                                                                                                                                              |\n| Background:    | CASA has reviewed state-of-design ADs applicable to RB211 engines and decided G-009-06-82 should be explicitly mandated for Australian aircraft.                                                                                                                              |\n\n![](image.001.png)\n\nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n4 April 2012","sortOrder":0},{"sectionNumber":"AD/RB211/43","sectionType":"part","heading":"AD/RB211/43","content":"## AD/RB211/43","sortOrder":1},{"sectionNumber":"Engine - IP Compressor Rotor and IP Turb","sectionType":"part","heading":"Engine - IP Compressor Rotor and IP Turbine Discs","content":"## Engine - IP Compressor Rotor and IP Turbine Discs","sortOrder":2},{"sectionNumber":"7/2012","sectionType":"part","heading":"7/2012","content":"## 7/2012","sortOrder":3}],"analysis":{"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific safety issue with specific engine components under specific conditions. The document explicitly states it is implementing a state-of-design AD from the UK CAA, which is the standard purpose of airworthiness directives."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 defined technical terms (N2 overspeed, IP - Intermediate Pressure)","Single, clear compliance trigger (N2 overspeed event)","No nested exceptions or conditional logic","References only one external document (Rolls-Royce Service Bulletin 72-5887)","Straightforward applicability criteria (specific engine model and aircraft types)"],"plain_english_summary":"This AD requires Australian operators and maintenance organisations to withdraw from service specific Rolls‑Royce RB211‑524 IP compressor rotor drums and IP turbine discs if they have experienced an N2 overspeed. It’s a mandatory safety step to remove parts that may have hidden damage after overspeed events, preventing possible engine failure and aligning Australian rules with the UK CAA directive."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"CASA has taken the state‑of‑design AD (UK CAA G‑009‑06‑82) and made it explicitly mandatory for Australian aircraft with RB211‑524 engines; this converts a foreign-design authority requirement into a directly binding domestic directive for the specified fleet."},"complexity_factors":["Technical subject matter: requirement targets specific engine components (IP compressor rotor drum and IP turbine discs) and an operational event (N2 overspeed).","Cross‑reference to external technical document: compliance depends on Rolls‑Royce Service Bulletin No. 72‑5887 Rev 4 (or later approved revision), creating dependency on manufacturer guidance.","Event‑triggered compliance: obligation applies \"following N2 overspeed,\" requiring operators to detect, document and react to discrete incidents.","Limited applicability: applies only to RB211‑524 engines installed in specified aircraft types (Boeing 747, 767, Lockheed L‑1011), narrowing but complicating operator identification and fleet management.","Regulatory linkage: implements a state‑of‑design AD (UK CAA G‑009‑06‑82) domestically, transferring obligations established elsewhere into Australian regulatory effect.","Compliance timing and logistics: effective date is specified (30 April 2012) and operators must withdraw parts and arrange replacements, creating operational and cost burdens."],"plain_english_summary":"This Airworthiness Directive requires operators of RB211‑524 engines fitted to specified Boeing 747, 767 and Lockheed L‑1011 aircraft to withdraw from service any IP (intermediate‑pressure) compressor rotor drum and IP turbine discs that have experienced an N2 overspeed, in accordance with Rolls‑Royce Service Bulletin No. 72‑5887 Revision 4 (or later approved revision). CASA says it is explicitly mandating the UK CAA AD; affected operators must identify overspeeded parts, remove them, and bear the cost and logistics of replacement to restore airworthiness."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rb211-43-engine-ip-compressor-rotor-and-ip-turbine-discs","history":"/api/acts/ad-rb211-43-engine-ip-compressor-rotor-and-ip-turbine-discs/history","analysis":"/api/acts/ad-rb211-43-engine-ip-compressor-rotor-and-ip-turbine-discs/analysis","conflicts":"/api/acts/ad-rb211-43-engine-ip-compressor-rotor-and-ip-turbine-discs/conflicts","importantCases":"/api/acts/ad-rb211-43-engine-ip-compressor-rotor-and-ip-turbine-discs/important-cases","documents":"/api/acts/ad-rb211-43-engine-ip-compressor-rotor-and-ip-turbine-discs/documents"}}