{"id":"F2006B02946","name":"AD/B737/47 - Left Engine Fuel Feed Tube","slug":"ad-b737-47-left-engine-fuel-feed-tube","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42288,"registerId":"commonwealth-F2006B02946-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/47 - Left Engine Fuel Feed Tube","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBoeing 737 Series Aeroplanes\n\nAD/B737/47 Left Engine Fuel Feed Tube 11/90\n\nApplicability: Model 737-300 and 737-400 series, listed in Boeing Service Bulletin 737-28-1084. Requirement: Unless already accomplished, action one of the following:\n\n    Inspect the left engine fuel feed tube assembly for proper clearance and chafing in accordance with Boeing Service Bulletin 737-28-1055 Revision 1.\n\n    2. Replace the left engine fuel feed tube assembly in accordance with Boeing Service Bulletin 737-28-1084, and verify minimum clearance between support structure and fuel tube in accordance with Boeing Service Bulletin 737-28-1055 Revision 1.\n\n    3. Replace the left engine fuel feed tube assembly in accordance with Boeing Service Bulletin 737-28-1084, and verify minimum clearance in accordance with Boeing Service Bulletin 737-28-1084 Revision 1.\n\nNote: FAA AD 90-15-03 Amdt 39-6650 refers.\n\nCompliance: 1. Prior to 31 January 1991.\n\n    2. Prior to 30 April 1991.\n\n    3. Prior to 30 April 1991.\n\nBackground: Reports of chafing of the left engine fuel feed tube in the wing/strut area have been received by the FAA. This condition could result in fuel leakage causing a potential engine strut fire hazard.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive targets reported chafing of the left engine fuel feed tube on specified 737-300/400 aircraft and requires inspection or replacement per referenced Boeing service bulletins within set deadlines; the scope aligns with that stated safety purpose and does not expand beyond it."},"complexity_factors":["Technical aircraft maintenance tasks (inspection, verification of clearance, and replacement) require qualified personnel and access to Boeing service bulletins.","Multiple compliance options with different deadlines increase administrative choice and record-keeping.","Applicability limited to specific models listed in Boeing SB 737-28-1084; operators must confirm applicability to their fleet.","Safety-critical consequence (fuel leak/fire) raises urgency but not regulatory ambiguity."],"plain_english_summary":"Requires operators of Boeing 737-300 and 737-400 aeroplanes listed in Boeing Service Bulletin 737-28-1084 to inspect or replace the left engine fuel feed tube and verify minimum clearance, using the specified Boeing service bulletins. Compliance deadlines are set (inspection by 31 Jan 1991; replacements by 30 Apr 1991). Operators are responsible for carrying out and funding the work and scheduling compliance. The directive responds to reported chafing that could lead to fuel leakage and an engine-strut fire hazard."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical defect. It has not expanded beyond its original purpose of mandating inspection/replacement of a single fuel system component on specific aircraft models."},"complexity_factors":["Short, single-purpose directive (approximately 200 words)","Only 3 defined compliance paths with clear alternative options","Minimal cross-referencing: references 3 Boeing Service Bulletins and 1 FAA AD","Simple conditional structure: 'Unless already accomplished' is the only exception clause","No nested definitions or interpretation section","Clear, fixed compliance dates rather than conditional triggers"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of certain Boeing 737‑300/400s to address chafing of the left engine fuel feed tube, which can cause fuel leaks and fire. It mandates corrective action—inspection or replacement plus clearance checks—under short compliance deadlines to remove the fire risk.\n\nIt affects affected aircraft listed in Boeing Service Bulletin 737‑28‑1084 and the maintenance personnel who must carry out the required inspections or replacements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-47-left-engine-fuel-feed-tube","history":"/api/acts/ad-b737-47-left-engine-fuel-feed-tube/history","analysis":"/api/acts/ad-b737-47-left-engine-fuel-feed-tube/analysis","conflicts":"/api/acts/ad-b737-47-left-engine-fuel-feed-tube/conflicts","importantCases":"/api/acts/ad-b737-47-left-engine-fuel-feed-tube/important-cases","documents":"/api/acts/ad-b737-47-left-engine-fuel-feed-tube/documents"}}