{"id":"F2006L01691","name":"AD/CFM56/9 Amdt 1 - HPTR Fan Disk Inspection","slug":"ad-cfm56-9-amdt-1-hptr-fan-disk-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":59448,"registerId":"commonwealth-F2006L01691-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/CFM56/9 Amdt 1 | HPTR Fan Disk Inspection | 7/2006 |\n| ----------------- | ------------------------ | ------ |\n\n| Applicability: | HPTR fan disks of all CFM International (CFMI) 56-2, 56-2A, 56-2B, 56-3, 56-3B and 56-3C engines.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Perform an Eddy current inspection of all HPTR discs with part numbers 1475M29PO1,1475M29PO2, 9514M69PO1, 9514M69PO4, 9514M69PO5, 9514M69PO6 and 9514M69PO9 with Serial numbers as listed in Table 1 of the applicable CFMI Service Bulletin (SB) as follows:1. CFM56-2 engines, in accordance with CFM56-2 SB No. 72-817 dated14 January 1997.2. CFM56-2A engines, in accordance with CFM56-2A SN No. 72-419, Revision 1, dated 31 January 1997.3. CFM56-2B engines, in accordance with CFM56-2B SB No. 72-561, Revision 1, dated 31 January 1997.4. CFM56-3, -3B, -3C engines in accordance with CFM56-3/ -3B/ -3C, SB No.72-843 dated 14 January 1997.All HPTR discs found cracked or gouged are to be removed from service.Note: DGAC AD 97-327(B) refers. |\n| Compliance:    | Within 30 days after the effective date of this AD, unless previously accomplished.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n|                | This Amendment becomes effective on 6 July 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| Background:    | This Directive is prompted by a report of a HPTR disc which was found to have a crack in a rim bolt hole during a routine shop visit eddy current inspection. The investigation revealed that the crack initiated from a gouge in the bolt hole. The gouge is the result of a drill break that occurred when the rim bolt hole was manufactured.                                                                                                                                                                                                                                                                                                                                                                                                               |\n\n|     | This amendment corrects a typographical error in part number listed for certain disks. The part number listed as 147M29PO1 should have read 1475M29PO1. The revised compliance period is to ensure that no disks have been omitted from the requirements of this AD due to the typographical error. |\n| --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n24 May 2006","sortOrder":0},{"sectionNumber":"AD/CFM56/9 Amdt 1","sectionType":"part","heading":"AD/CFM56/9 Amdt 1","content":"## AD/CFM56/9 Amdt 1","sortOrder":1},{"sectionNumber":"HPTR Fan Disk Inspection","sectionType":"part","heading":"HPTR Fan Disk Inspection","content":"## HPTR Fan Disk Inspection","sortOrder":2},{"sectionNumber":"7/2006","sectionType":"part","heading":"7/2006","content":"## 7/2006","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Amendment corrects a typographical error in a part number (147M29PO1 → 1475M29PO1) and clarifies the compliance wording so no disks are omitted. It does not broaden the subject matter of the directive, add new obligations, or expand affected engine models; it preserves the original safety inspection requirement."},"complexity_factors":["Short single‑issue directive (one mandated action)","7 distinct HPTR disk part numbers listed","Multiple engine variants referenced (CFM56‑2, ‑2A, ‑2B, ‑3/‑3B/‑3C) requiring cross‑reference to variant‑specific SBs","Dependency on Table 1 in the CFMI Service Bulletins (external document cross‑reference and serial‑number matching)","One short compliance requirement with a single 30‑day deadline","Amendment corrects a typographical error in a part number (small but critical edit)"],"plain_english_summary":"**What this directive does (mechanical effect)**\n\n- Orders a one-time Eddy current (non‑destructive electrical) inspection of specific high‑pressure turbine rotor (HPTR) fan disks used in a range of CFM56 engine models. The inspection must follow the inspection procedures and serial‑number lists in the relevant CFM International Service Bulletin (SB) for each engine variant (see \"Requirement\").\n- Any HPTR disk found to be cracked or gouged must be removed from service.\n- The inspection must be completed within 30 days of the AD taking effect (the Amendment is effective 6 July 2006) (see \"Compliance\").\n- The Amendment corrects a typographical error in a part number (147M29PO1 corrected to 1475M29PO1) and adjusts the compliance wording so no disks are unintentionally omitted (see \"Background\" / amendment note).\n\n**Who this affects**\n\n- Aircraft operators, owners and lessors whose aircraft are fitted with CFM International (CFMI) CFM56 engines of the following variants: 56‑2, 56‑2A, 56‑2B, 56‑3, 56‑3B and 56‑3C (see \"Applicability\").\n- Maintenance, repair and overhaul (MRO) organisations and shops that perform eddy‑current inspections and repairs on CFM56 HPTR disks.\n- Parts suppliers and inventories holding the listed HPTR disk part numbers and serial numbers (identified in Table 1 of the applicable CFMI SBs).\n\n**Why it matters (safety and mechanical rationale)**\n\n- The directive was prompted by a discovered rim‑bolt hole crack that initiated from a gouge created during manufacture (a drill break). A cracked HPTR disk is a structural failure risk for the engine; the AD requires inspection to detect such cracks before they propagate (see \"Background\").\n\n**How operators must comply (practical steps)**\n\n- Identify whether installed HPTR disks match the listed part numbers and serial numbers in Table 1 of the relevant CFMI Service Bulletin for your engine variant (CFM56‑2, ‑2A, ‑2B, ‑3/‑3B/‑3C SBs referenced in the Requirement).\n- Perform the Eddy current inspection in accordance with the procedure in the applicable SB for that engine model.\n- If inspection finds a crack or gouge, remove the disk from service immediately.\n\n**Immediate costs and who pays**\n\n- Operators pay for the inspection (labour and possible shop visits), potential removal and replacement of disks, and associated aircraft downtime. MROs incur the labour and testing equipment effort; parts suppliers may be impacted if replacement disks are required.\n\n**Implementation and operational effects (behavioural change)**\n\n- Operators will need to schedule short‑term maintenance windows to perform the mandated inspection within 30 days.\n- MROs with eddy‑current capability will receive work; operators without in‑house capability may need to transfer aircraft for inspection or contract external shops.\n- If disks are removed, aircraft may be grounded until replacements are sourced and fitted, affecting route planning and utilization.\n\n**Compliance, risk and administrative notes**\n\n- The AD cross‑references specific CFMI SBs for procedures and serial‑number lists. Correct identification of part numbers and serial numbers is essential to avoid both over‑ and under‑compliance (the Amendment fixed a typographical error in a part number to prevent omission) (see amendment note).\n- Effective compliance requires qualified personnel and the correct Eddy current test setup; incorrect inspection technique risks false negatives or unnecessary removals.\n\n**Market‑oriented effects to note**\n\n- The directive creates immediate demand for inspection and possible replacement parts, benefiting qualified MROs and parts suppliers.\n- Operators with larger fleets or spare engines will be better placed to absorb downtime; smaller operators may face proportionally higher operational disruption and cost.\n- The AD restricts operators’ choice (they must inspect and remove defective disks), but it does not change ownership or contractual rights beyond requiring compliance to continue to operate legally.\n\n(References: Applicability; Requirement; Compliance; Background; amendment note correcting part number and compliance wording.)"},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is an amendment to an existing Airworthiness Directive. The scope remains unchanged — it corrects a typographical error in a part number (147M29PO1 to 1475M29PO1) and adjusts the compliance period to ensure coverage. The fundamental safety purpose (inspecting HPTR disks for cracks) and affected engine models remain identical to the original AD."},"complexity_factors":["Multiple specific part numbers and serial numbers requiring cross-referencing with manufacturer service bulletins","Six different engine sub-models each with different service bulletin references","Technical aviation terminology (eddy current inspection, HPTR, shop visit)","Conditional compliance based on whether inspection was 'previously accomplished'","Reference to foreign aviation authority directive (DGAC AD 97-327(B)) requiring external cross-check"],"plain_english_summary":"This AD mandates immediate eddy-current inspections of High Pressure Turbine Rotor fan disks in certain CFM56 engines used on aircraft like the Boeing 737, removing any cracked or gouged disks from service. It affects operators and maintenance organisations for those engine models. It matters because a manufacturing defect led to a discovered crack that could cause catastrophic disk failure; the amendment corrects a part-number typo and restarts the 30‑day compliance clock."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cfm56-9-amdt-1-hptr-fan-disk-inspection","history":"/api/acts/ad-cfm56-9-amdt-1-hptr-fan-disk-inspection/history","analysis":"/api/acts/ad-cfm56-9-amdt-1-hptr-fan-disk-inspection/analysis","conflicts":"/api/acts/ad-cfm56-9-amdt-1-hptr-fan-disk-inspection/conflicts","importantCases":"/api/acts/ad-cfm56-9-amdt-1-hptr-fan-disk-inspection/important-cases","documents":"/api/acts/ad-cfm56-9-amdt-1-hptr-fan-disk-inspection/documents"}}