{"id":"F2006B08530","name":"AD/CFM56/5 - High Pressure Compressor 1-2 Spool","slug":"ad-cfm56-5-high-pressure-compressor-1-2-spool","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51290,"registerId":"commonwealth-F2006B08530-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CFM56/5 - High Pressure Compressor 1-2 Spool","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCFM International Turbine Engines \\- CFM56 Series\n\nAD/CFM56/5 High Pressure Compressor 1-2 Spool 5/95\n\nApplicability: All CFM56-5-A Series engines incorporating No.3 bearing aft air/oil seal, P/N 1364M71G02.\n\nRequirement: 1. Inspect affected engines in accordance with CFM56-5 Service Bulletin 72-440, Revision 1.\n\n2. Replace No.3 bearing aft air/oil seal, P/N 1364M71G02, in accordance with CFM56-5 Service Bulletin 72-440, Revision 1.\n\nNote: DGAC AD 94-272(B)R1 also refers.\n\nCompliance: As detailed in the Requirement Document effective from 27 April 1995.\n\nBackground: It has been determined that a lack of running clearance may exist between the referenced stationary No.3 bearing aft air/oil seal and the stage 1 HPC disc bore. There is a potential for contact between the two parts in service which will result in rubbing/scratching of the disc bore forward corner. Such damage could lead to an uncontained failure of the disc.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — addressing a specific mechanical defect in a specific engine component. There is no evidence of scope creep; it remains a targeted safety intervention for a defined hardware issue."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined applicability criterion (specific engine series and part number)","Simple two-step compliance requirement (inspect and replace)","No nested exceptions or conditional logic","Single cross-reference to a French aviation authority directive (DGAC AD 94-272(B)R1) for informational purposes only","Clear, unambiguous language with minimal technical jargon explained through context"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft engines.\n\n**What it does:**\nThis directive requires airlines and aircraft operators to inspect and replace a specific faulty part in certain jet engines. The part in question is the \"No.3 bearing aft air/oil seal\" (a component that keeps oil in and air out of a bearing assembly) in CFM56-5-A series engines.\n\n**Why it matters:**\nThe seal can rub against a rotating disc in the engine's high-pressure compressor. This contact can scratch or damage the disc, potentially causing it to break apart during flight — an \"uncontained failure\" where metal fragments could escape the engine casing, endangering the aircraft and passengers.\n\n**Who must comply:**\nAnyone operating aircraft with CFM56-5-A series engines that have the specific seal part number 1364M71G02 installed.\n\n**What must be done:**\n- Inspect the engines following CFM International's Service Bulletin 72-440 (Revision 1)\n- Replace the faulty seal with a corrected part, following the same service bulletin\n\n**When:**\nBy the deadlines specified in the original requirement document, with the directive taking effect from 27 April 1995."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive’s scope is limited to CFM56-5-A series engines that have the specific No.3 bearing aft air/oil seal, P/N 1364M71G02, and requires inspection and replacement per the manufacturer’s service bulletin. The actions required directly match the safety concern identified (contact damage between the seal and the stage 1 HPC disc bore). The AD does not expand obligations beyond that defined applicability and the procedural steps referenced in the Requirement Document (Applicability, Requirement, Background, Compliance)."},"complexity_factors":["Technical specificity: applies to a narrow population defined by engine model and a single part number (Applicability).","Dependence on an external technical document (CFM56-5 Service Bulletin 72-440, Revision 1) for procedural detail (Requirement).","Safety-critical maintenance work requiring certified maintenance organisations and parts availability (Requirement, Compliance).","Clear compliance deadline/reference date is externalised to the Requirement Document effective date (Compliance).","Cross-reference to a foreign airworthiness directive (DGAC AD 94-272(B)R1) that operators may consult (Note)."],"plain_english_summary":"This AD requires operators of CFM56-5-A engines fitted with No.3 bearing aft air/oil seal P/N 1364M71G02 to inspect and, where required, replace that seal per CFM56‑5 Service Bulletin 72‑440 Rev.1. It was issued because seal-to-disc contact can rub the stage‑1 HPC disc bore, risking disc damage or uncontained failure. The compliance burden (inspection, parts, downtime) falls on operators/engine owners."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cfm56-5-high-pressure-compressor-1-2-spool","history":"/api/acts/ad-cfm56-5-high-pressure-compressor-1-2-spool/history","analysis":"/api/acts/ad-cfm56-5-high-pressure-compressor-1-2-spool/analysis","conflicts":"/api/acts/ad-cfm56-5-high-pressure-compressor-1-2-spool/conflicts","importantCases":"/api/acts/ad-cfm56-5-high-pressure-compressor-1-2-spool/important-cases","documents":"/api/acts/ad-cfm56-5-high-pressure-compressor-1-2-spool/documents"}}