{"id":"F2006B08527","name":"AD/CFM56/23 - Engine Main Fuel Pumps","slug":"ad-cfm56-23-engine-main-fuel-pumps","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51281,"registerId":"commonwealth-F2006B08527-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# ![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nCFM International Turbine Engines \\- CFM56 Series","sortOrder":0},{"sectionNumber":"AD/CFM56/23 Engine Main Fuel Pumps 9/200","sectionType":"part","heading":"AD/CFM56/23 Engine Main Fuel Pumps 9/2004","content":"# AD/CFM56/23 Engine Main Fuel Pumps 9/2004\n\nApplicability: CFM INTERNATIONAL CFM56-2C, CFM56-3 series and CFM56-5 series turbofan engines fitted with fuel pumps with solid bronze bearings.\n\nNote 1: These engines are installed on, but not limited to, Airbus Industrie A319 and A320, Boeing 737, and McDonnell Douglas DC-8 aeroplanes.\n\nRequirement: 1. Replace main fuel pumps equipped with solid bronze bearings with pumps equipped with bi-metal aluminium/bronze bearings in according with the applicable Service Bulletin as listed below.\n\nService Bulletin (CFM56-2C) 73-0104 Revision 3 dated December 17, 2003\n\nService Bulletin (CFM56-3) 73-0120 Revision 5 dated December 17, 2003\n\nService Bulletin (CFM56-5A) 73-0126 Revision 4 dated December 17, 2003.\n\n2. Do not install a main fuel pump with bronze bearings.\n\nNote 2: FAA AD 2004-10-13 Amdt 39-13643 and DGAC AD F-2004-095 refer.\n\nCompliance: For requirement 1: Either at next engine shop visit, or at next main fuel pump replacement, or before January 1st, 2007, whichever occurs first.\n\nFor the purpose of this Directive, an engine shop visit is defined as any maintenance that includes the separation of an engine casing flange.\n\nFor requirement 2: After the effective date of this Directive.\n\nThis Airworthiness Directive becomes effective on 2 September 2004.","sortOrder":1}],"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":2,"scope_assessment":{"changed":false,"description":"This Directive addresses a narrowly defined unsafe condition — main fuel pumps fitted with solid bronze bearings on specified CFM56 engine series — and mandates replacement and a prohibition on future installation. The measures and applicability are consistent with that single technical purpose and do not materially expand the Directive's scope beyond the original safety-focused intent."},"complexity_factors":["Short, single-issue text (pump replacement and installation prohibition)","3 engine-series groups named (CFM56-2C, -3 series, -5 series)","3 specific manufacturer service bulletins referenced (each with revision and date)","One conditional compliance structure (next engine shop visit OR next pump replacement OR fixed date)","One defined term introduced ('engine shop visit' defined as separation of engine casing flange)","Prohibition on future installations (simple negative obligation)","Cross-references to FAA and DGAC ADs (informational only)"],"plain_english_summary":"**What this Directive does (mechanically)**\n\n- **Who is affected:** Operators and maintainers of CFM International turbofan engines CFM56-2C, CFM56-3 series and CFM56-5 series fitted with main fuel pumps that have solid bronze bearings. (Note: those engines are commonly fitted to Airbus A319/A320, Boeing 737 and McDonnell Douglas DC-8 aircraft, among others.)\n\n- **Required actions (Requirement):**\n  - Replace any main fuel pump that uses solid bronze bearings with a pump that uses bi-metal aluminium/bronze bearings, following the applicable CFM service bulletin cited in the Directive (each engine series has its own bulletin and revision listed). (Requirement 1)\n  - Do not install main fuel pumps with solid bronze bearings after the Directive becomes effective. (Requirement 2)\n\n- **When it must be done (Compliance):**\n  - Replace pumps either at the next engine shop visit, or at the next time a main fuel pump is replaced, or by 1 January 2007 — whichever happens first. The Directive defines an \"engine shop visit\" as any maintenance that involves separating an engine casing flange. (Compliance for Requirement 1)\n  - The prohibition on installing bronze-bearing pumps applies from the Directive's effective date. (Compliance for Requirement 2)\n\n- **How to do it:** Follow the detailed instructions in the listed CFM service bulletins for the applicable engine model and revision. The Directive also cross-references related FAA and DGAC airworthiness directives.\n\n**Why this matters (stated purpose and practical consequences)**\n\n- The Directive is issued to correct an identified unsafe condition relating to main fuel pumps fitted with solid bronze bearings. The manufacturer service bulletins cited provide the technical instructions for replacement.\n\n- Who pays and who decides: Aircraft operators and their maintenance organisations pay for the new pumps, associated labour and downtime. The regulator (a CASA delegate) mandates the action and sets the deadlines; the operator/maintainer decides the exact timing within the compliance windows and arranges the work.\n\n- Practical trade-offs and implementation considerations:\n  - Cost and downtime: Replacing pumps may require parts procurement, shop access and labour; some operators will need to schedule earlier maintenance visits to meet the deadline if pump replacement would not otherwise occur. This is an up-front cost for operators and maintenance facilities.\n  - Supply-chain effects: Suppliers of the new bi-metal pumps gain demand; suppliers of bronze-bearing pumps lose future installation opportunities because installation of bronze-bearing pumps is prohibited after the effective date.\n  - Compliance burden: Operators must track affected engines/pumps, ensure replacement by the deadlines or at the next shop visit, and ensure no bronze-bearing pump is installed thereafter.\n  - Implementation risk: If replacement parts are scarce or if shop capacity is constrained, meeting the earliest applicable compliance trigger (next shop visit or pump replacement) could force rescheduling of maintenance or cause temporary dispatch limitations.\n\n**Reference mechanics in the text:**\n- Applicability: lists engine models and limits the AD to pumps with solid bronze bearings. (Applicability)\n- Requirement 1 and Requirement 2: prescribe replacement and prohibition. (Requirement)\n- Compliance: sets the timing options and defines \"engine shop visit.\" (Compliance)\n\n**Cross-references:** The AD cites specific CFM service bulletins by engine type and revision and refers to FAA AD 2004-10-13 and DGAC AD F-2004-095 for related regulatory actions.\n\n(End of summary.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"N/A — this is a standalone AD with no prior version to compare against; it addresses a specific, narrow safety issue without scope creep"},"complexity_factors":["Single, specific technical requirement (bearing replacement)","Only 3 engine series affected with clear identification","Simple compliance timeline with three alternative triggers (shop visit / replacement / fixed date)","One defined term ('engine shop visit')","No nested exceptions or conditional logic","Short document (approximately 250 words)","Cross-references limited to 3 service bulletins and 2 foreign ADs for information only"],"plain_english_summary":"This CASA Airworthiness Directive requires replacement of main fuel pumps fitted with solid bronze bearings in CFM56-2C, -3 and -5 engines and bans installation of such pumps from 2 September 2004. It affects operators and maintenance organisations for Airbus A319/A320, Boeing 737 and McDonnell Douglas DC-8 types and addresses a safety risk from bearing failures. Replacements are mandated by the earlier of the next engine shop visit, next pump change, or 1 January 2007."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cfm56-23-engine-main-fuel-pumps","history":"/api/acts/ad-cfm56-23-engine-main-fuel-pumps/history","analysis":"/api/acts/ad-cfm56-23-engine-main-fuel-pumps/analysis","conflicts":"/api/acts/ad-cfm56-23-engine-main-fuel-pumps/conflicts","importantCases":"/api/acts/ad-cfm56-23-engine-main-fuel-pumps/important-cases","documents":"/api/acts/ad-cfm56-23-engine-main-fuel-pumps/documents"}}