{"id":"F2009L02332","name":"AD/RB211/40 - Low Pressure Turbine Casing","slug":"ad-rb211-40-low-pressure-turbine-casing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":79105,"registerId":"commonwealth-F2009L02332-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/RB211/40 | Low Pressure Turbine Casing | 7/2009 |\n| ----------- | --------------------------- | ------ |\n\n| Applicability: | RB211-524C2-19 and RB211-524C2-B-19 engines, all serial numbers.Note 1: These engines are known to be installed, but not limited to Boeing 747 series aircraft.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Carry out the actions defined in Section 3. Accomplishment Instructions ofRolls-Royce Non-Modification Service Bulletin (NMSB) No. 72-AG076.2. Repeat the actions detailed in Requirement 1 of this AD.Note 2: EASA AD 2009-0083 dated 16 April 2009 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| Compliance:    | For Requirement 1:If at the effective date of this AD the life of the LPT Casing is known and less than 4,500 Cycles Since New (CSN) - Before the life of the LPT casing has reached 4,500 CSN.If at the effective date of this AD the life of the LPT Casing is known and greater than or equal to 4,500 CSN and the life of the LPT casing since last full Fluorescent Penetrant Inspection (FPI) is either known and greater than 4,500 Cycles or not known - At the next shop visit.If at the effective date of this AD the life of the LPT Casing is known and greater than or equal to 4,500 CSN and the life of the LPT casing since last full FPI is known and less than 4,500 Cycles - Before the life of the LPT Casing has reached 4,500 Cycles since last full FPI.If at the effective date of this AD the life of the LPT Casing is not known and the life of the LPT casing since last full FPI is either not known or greater than or equal to 4,500 Cycles - At the next shop visit.If at the effective date of this Airworthiness Directive the life of the LPT Casing is not known and the life of the LPT casing since last full FPI is known and less than 4,500 Cycles - Before the life of the LPT Casing has reached 4,500 Cycles since last full FPI. |\n\n|             | For Requirement 2:At intervals not exceeding 4,500 Cycles.                                                                                                                                                                                                                                                                                                                                                                                                     |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This Airworthiness Directive becomes effective on 2 July 2009.                                                                                                                                                                                                                                                                                                                                                                                                 |\n| Background: | A number of LPT casings have been found cracked during engine shop visit. Cracking of the LPT casing reduces the capability of the casing to contain debris in the event of an LPT stage 1 blade failure. Therefore, blade failure in an engine featuring a cracked LPT casing may result in release of uncontained high energy debris. For the reason described above, this AD requires repetitive inspections and corrective actions, depending on findings. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n19 May 2009","sortOrder":0},{"sectionNumber":"AD/RB211/40","sectionType":"part","heading":"AD/RB211/40","content":"## AD/RB211/40","sortOrder":1},{"sectionNumber":"Low Pressure Turbine Casing","sectionType":"part","heading":"Low Pressure Turbine Casing","content":"## Low Pressure Turbine Casing","sortOrder":2},{"sectionNumber":"7/2009","sectionType":"part","heading":"7/2009","content":"## 7/2009","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific safety defect in specific Rolls-Royce engine models. The conditional compliance structure, while intricate, is standard for aviation maintenance directives where aircraft have varying operational histories. The scope has not expanded beyond the original safety concern of cracked LPT casings."},"complexity_factors":["Multiple conditional compliance pathways based on two variables (total cycles since new AND cycles since last inspection)","Five distinct compliance scenarios with different deadlines depending on known/unknown maintenance history","Technical aviation terminology requiring specialized knowledge (CSN, FPI, shop visit, LPT casing)","Cross-reference to external technical document (Rolls-Royce NMSB 72-AG076) for actual inspection procedures","Reference to European aviation safety regulation (EASA AD 2009-0083) for context"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspections of the Low Pressure Turbine (LPT) casing on Rolls‑Royce RB211‑524C2‑19 and RB211‑524C2‑B‑19 engines used on Boeing 747s to detect and fix cracks that could allow a broken blade to puncture the engine and damage aircraft or harm people. Affected operators must perform the initial inspection per Rolls‑Royce NMSB 72‑AG076 (timing based on cycles/inspection history) and repeat inspections every 4,500 flight cycles. Effective 2 July 2009."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The Directive's scope is limited to RB211‑524C2‑19 and RB211‑524C2‑B‑19 engines (all serial numbers) and mandates inspections and corrective actions per the referenced Rolls‑Royce service bulletin. The text contains no indication of an expanded or narrowed scope relative to the stated applicability; it sets initial and repetitive inspection requirements to address the identified cracking risk."},"complexity_factors":["Conditional compliance rules with multiple timing branches based on LPT casing life (Cycles Since New) and cycles since last full Fluorescent Penetrant Inspection (FPI) (see 'Compliance' section).","Repetitive inspection interval requirement of 'not exceeding 4,500 cycles' for ongoing compliance (see 'For Requirement 2').","Dependence on an external technical document: Rolls‑Royce NMSB No. 72‑AG076.2, Section 3, for the detailed accomplishment instructions (see 'Requirement').","Applicability limited to specific engine models (RB211‑524C2‑19 and RB211‑524C2‑B‑19) but applies to all serial numbers, affecting fleet operators (see 'Applicability').","Technical inspection method referenced (full Fluorescent Penetrant Inspection) and the need to interpret 'shop visit' timing for some compliance triggers (see 'Compliance').","Multiple 'unknown life' scenarios that require different timing for initial inspection, creating administrative and record‑keeping burdens (see 'Compliance' branches for unknown life).","Corrective actions required depending on findings, introducing potential repair cost and downtime obligations (see 'Requirement' and 'Background').","Cross‑reference to EASA AD 2009‑0083 introduces international regulatory alignment considerations (see Note 2).","Effective date and retroactive application rules (effective 2 July 2009) impose immediate obligations on operators after issuance (see 'This Airworthiness Directive becomes effective on 2 July 2009').","Safety rationale tied to containment capability of the LPT casing, linking inspection obligations to a specific failure consequence (uncontained high‑energy debris) which must be verified and mitigated during maintenance (see 'Background')."],"plain_english_summary":"This Airworthiness Directive requires operators of Rolls‑Royce RB211‑524C2‑19 and RB211‑524C2‑B‑19 engines to carry out the inspection and corrective actions set out in Rolls‑Royce NMSB No. 72‑AG076.2. Initial compliance timing depends on the LPT casing life and the time since the last full fluorescent penetrant inspection; inspections must be repeated at intervals not exceeding 4,500 cycles.\n\nIt applies to operators (commonly on Boeing 747s) because cracked low‑pressure turbine casings can allow release of uncontained high‑energy debris; compliance changes inspection scheduling and requires repairs when cracks are found."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-rb211-40-low-pressure-turbine-casing","history":"/api/acts/ad-rb211-40-low-pressure-turbine-casing/history","analysis":"/api/acts/ad-rb211-40-low-pressure-turbine-casing/analysis","conflicts":"/api/acts/ad-rb211-40-low-pressure-turbine-casing/conflicts","importantCases":"/api/acts/ad-rb211-40-low-pressure-turbine-casing/important-cases","documents":"/api/acts/ad-rb211-40-low-pressure-turbine-casing/documents"}}