{"id":"F2009L00214","name":"AD/CFM56/28 - Low Pressure Turbine Rear Frame","slug":"ad-cfm56-28-low-pressure-turbine-rear-frame","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":76678,"registerId":"commonwealth-F2009L00214-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"CFM International Turbine Engines - CFM5","sectionType":"division","heading":"CFM International Turbine Engines - CFM56 Series","content":"### CFM International Turbine Engines - CFM56 Series\n\n| AD/CFM56/28 | Low Pressure Turbine Rear Frame | 3/2009 DM |\n| ----------- | ------------------------------- | --------- |\n\n| Applicability: | CFM International CFM56-7B turbofan engines equipped with a low pressure turbine (LPT) rear frame part number (P/N) 340-166-254-0, 340-166-255-0, 340-166-256-0, 340-166-257-0, 340-166-258-0, 340-166-259-0, 340-177-551-0, 340-177-552-0, 340-177-553-0, 340-177-554-0, 340-177-555-0, 340-177-556-0.Note 1: These engines are known to be installed on, but not limited to, Boeing 737series aeroplanes. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Amend the approved operator maintenance programme to incorporate the new LCF life limits for LPT rear frame P/N 340-166-254-0, 340-166-255-0, 340-166-256-0, 340-166-257-0, 340-166-258-0, 340-166-259-0, 340-177-551-0, 340-177-552-0, 340-177-553-0, 340-177-554-0, 340-177-555-0, 340-177-556-0, in accordance with the CFM56-7B ESM chapter 05 Temporary Revision (TR) 05-0097, 05-0098, and 05-0099, as applicable or subsequent revisions of the Engine Shop Manual following Revision 38 that incorporate these Temporary Revisions.2. If the number of total cycles accumulated by a LPT rear frame P/N 340-166-254-0, 340-166-255-0, 340-166-256-0, 340-166-257-0, 340-166-258-0, 340-166-259-0, 340-177-551-0, 340-177-552-0, 340-177-553-0, 340-177-554-0, 340-177-555-0, 340-177-556-0 cannot be positively established, remove and replace the LPT rear frame or perform the inspections in accordance with CFM56-7B Service Bulletin S/B 72-0558 revision 2, or CFM56-7B Service Bulletin S/B 72-0579 revision 4, as applicable.The use of later approved revisions of the Service Bulletins is acceptable for compliance with the requirements of this AD.Note 2: The number of total cycles accumulated of the LPT rear frame is the sum of the number of cycles accumulated before and after compliance with CFM56-7B S/B 72-0527.Note 3: EASA AD 2009-0009 dated 15 January 2009 refers. |\n| Compliance: | For Requirement 1 - Within 30 days after the effective date of this AD.For Requirement 2 - Within 300 cycles after the effective date of the AD. |\n\n| | This Airworthiness Directive becomes effective on 28 January 2009. |\n| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Background: | The LPT rear frame part numbers detailed in this AD were introduced by the CFM56-7B Service Bulletin S/B 72-0527 revision 02 issued 21 January 2008. They are obtained by modifying (reworking) older P/N LPT frames.Before the issue of the CFM56-7B Engine Shop Manual (ESM) Temporary Revisions (TR) 05-0097, 05-0098, and 05-0099 on September 19, 2008, the concerned LPT rear frames were neither subject to a life limit nor to a mandatory inspection.This AD is issued to make sure that all operators are informed about the Low Cycle Fatigue (LCF) life limits or mandatory inspections affecting these new P/N and revise their aircraft maintenance programs accordingly. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n23 January 2009","sortOrder":0},{"sectionNumber":"AD/CFM56/28","sectionType":"part","heading":"AD/CFM56/28","content":"## AD/CFM56/28","sortOrder":1},{"sectionNumber":"Low Pressure Turbine Rear Frame","sectionType":"part","heading":"Low Pressure Turbine Rear Frame","content":"## Low Pressure Turbine Rear Frame","sortOrder":2},{"sectionNumber":"3/2009 DM","sectionType":"part","heading":"3/2009 DM","content":"## 3/2009 DM","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"},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"The AD expands the maintenance scope for specified reworked LPT rear-frame P/Ns by imposing LCF life limits and mandatory inspection/replacement requirements where none existed before; operators must amend approved maintenance programmes and address frames with unknown cycle histories."},"complexity_factors":["Multiple specific part numbers listed — requires accurate fleet identification and record checks.","Introduces LCF life limits into approved maintenance programmes (Requirement 1) — requires regulatory amendment and operator administrative action within 30 days.","Conditional compliance path when total cycles cannot be established (Requirement 2) — choice between replacement or inspections per S/Bs 72-0558 rev 2 or 72-0579 rev 4.","Reliance on external technical documents: Engine Shop Manual Temporary Revisions (TR 05-0097/98/99) and multiple Service Bulletins — operators must track approved revisions.","Time-based and usage-based compliance windows (30 days; 300 cycles) — operational planning and tracking implications.","Record-keeping complexity: total cycles must sum cycles before and after prior S/B 72-0527 (note about positive establishment of cycles).","Acceptability of later approved revisions adds discretionary judgment about applicable revisions.","Background change in part status: P/Ns were created by a 2008 rework and previously had no life limits, so operators must retrofit compliance into existing fleets."],"plain_english_summary":"This AD requires operators of CFM56-7B engines with the listed LPT rear-frame part numbers to add Low-Cycle Fatigue (LCF) life limits to their maintenance programs (Requirement 1) and, if a frame's total cycles cannot be positively established, to replace the frame or perform inspections per specified CFM56 service bulletins (Requirement 2). CASA issued the AD; operators bear the cost of programme amendments, inspections or replacements. Deadlines: 30 days for Requirement 1 and within 300 cycles for Requirement 2."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific safety issue with specific part numbers on specific engine models. The instrument does not expand beyond its original purpose of mandating life limits and inspections for these newly introduced LPT rear frames."},"complexity_factors":["Multiple specific part numbers listed (12 different P/Ns) with near-identical numbering schemes","Cross-references to three separate manufacturer documents (ESM Temporary Revisions 05-0097, 05-0098, 05-0099) and two Service Bulletins (S/B 72-0558 rev 2, S/B 72-0579 rev 4)","Conditional logic: Requirement 2 only applies if flight cycles 'cannot be positively established'","Technical aviation terminology requiring specialised knowledge (LCF life limits, cycles, Temporary Revisions, Service Bulletins)","Dual compliance timeline (30 days vs 300 cycles depending on requirement)","Reference to foreign regulatory instrument (EASA AD 2009-0009) for context"],"plain_english_summary":"This mandatory CASA Airworthiness Directive targets certain CFM56-7B low‑pressure turbine rear frames on Boeing 737s, introducing required life limits and traceability where none existed. Operators must update maintenance programs and ensure frames are inspected or removed if their service life can’t be established. It affects airlines and maintenance organisations using the listed parts and aims to prevent low‑cycle fatigue–related cracks or failures by enforcing tracking, inspection, and retirement of aging frames."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cfm56-28-low-pressure-turbine-rear-frame","history":"/api/acts/ad-cfm56-28-low-pressure-turbine-rear-frame/history","analysis":"/api/acts/ad-cfm56-28-low-pressure-turbine-rear-frame/analysis","conflicts":"/api/acts/ad-cfm56-28-low-pressure-turbine-rear-frame/conflicts","importantCases":"/api/acts/ad-cfm56-28-low-pressure-turbine-rear-frame/important-cases","documents":"/api/acts/ad-cfm56-28-low-pressure-turbine-rear-frame/documents"}}