{"id":"F2006B03244","name":"AD/B747/64 Amdt 4 - Wing Centre Section - Front Spar Lower Chord Splice Fitting Bolts","slug":"ad-b747-64-amdt-4-wing-centre-section-front-spar-lower-chord-splice-fitting-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42668,"registerId":"commonwealth-F2006B03244-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/64 Amdt 4 - Wing Centre Section - Front Spar Lower Chord Splice Fitting Bolts","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 747 Series Aeroplanes\n\nAD/B747/64\n\nAmdt 4\n\n  \n\nWing Centre Section \\- Front Spar Lower Chord Splice Fitting Bolts\n\n  \n9/90\n\nApplicability: All models B747-200 and -300 series aeroplanes with line numbers 1 to 720. Requirement: Action in accordance with FAA AD 90-11-08 Amdt 39-6609, Parts A, B and C.\n\nNote 1: Boeing Alert SB 747-57A2247 Rev 3 refers.\n\nNote 2: FAA AD 88-11-11 referred to in the previous issue of this CAO Directive.\n\nCompliance: For Part A: Unless previously accomplished within the last 350 hours time in service prior to 6 September 1990, within 50 hours time in service after 6 September 1990, and thereafter at intervals not exceeding 400 hours time in service until terminating action is accomplished in accordance with the Requirement Document.\n\nFor Part B: Unless already accomplished, Prior to 31 July 1993\\. For Part C: Unless already accomplished, Prior to 31 July 1993.\n\nBackground: Country of origin AD. There have been overseas reports of fuel leakage into the forward cargo compartment which could result in a fire and substantial damage. Amendment 4 to this Directive references latest FAA AD as the Requirement document. This requires visual inspections as per the previous CAO Directive issue, but, requires terminating actions and inspection of centre wing fuel tank secondary fuel barriers to be accomplished prior to specified date.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"Amendment 4 updates the Requirement to reference FAA AD 90-11-08 (replacing the earlier FAA AD 88-11-11), and adds explicit requirements for terminating actions and inspection of centre wing fuel tank secondary fuel barriers to be completed by specified dates (Background; Requirement; Compliance)."},"complexity_factors":["Cross-reference to foreign requirement document: mandates compliance 'in accordance with FAA AD 90-11-08 Amdt 39-6609, Parts A, B and C' (Requirement).","Multiple, staggered compliance timelines: Part A inspection window and recurring interval rules (within 50 hours after 6 Sep 1990 unless recently done; thereafter intervals not exceeding 400 hours) introduce scheduling complexity (Compliance: Part A).","Fixed deadlines for terminating actions and other work: Parts B and C must be accomplished 'Prior to 31 July 1993' unless already done (Compliance: Parts B and C).","Referenced service instruction: Boeing Alert SB 747-57A2247 Rev 3 is noted, creating dependency on manufacturer guidance (Note 1).","Limited applicability: applies only to B747-200 and -300 with specific line numbers 1–720, requiring accurate fleet records (Applicability).","Safety-critical consequence and inspection scope: addresses fuel leakage into forward cargo compartment and requires inspection of centre wing fuel tank secondary fuel barriers as terminating action, increasing inspection scope and potential repair work (Background).","Record-keeping and maintenance burden: recurring inspections until terminating action mean ongoing monitoring, scheduling and cost for operators (inferred from Compliance and Requirement)."],"plain_english_summary":"This airworthiness directive requires operators of Boeing 747-200 and -300 aeroplanes (line numbers 1–720) to carry out inspections and corrective work on the wing centre front spar lower chord splice fitting bolts, following FAA AD 90-11-08 (Parts A–C). It sets short-term inspection windows, recurring inspection intervals, and deadlines for specified terminating actions.\n\nThe measure aims to prevent fuel leakage into the forward cargo compartment (a fire risk). Compliance places inspection, maintenance and any corrective/terminating work obligations on aircraft operators and their maintenance organisations."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original directive (implied by 'Amendment 4') appears to have been a basic inspection requirement. This amendment significantly expanded the scope by adding 'terminating actions' (permanent repairs) and new requirements to inspect 'centre wing fuel tank secondary fuel barriers' — going beyond mere ongoing inspections to require permanent fixes and additional fuel system checks by a 1993 deadline."},"complexity_factors":["Short, single-purpose document (one specific mechanical issue on one aircraft type)","Only 3 defined compliance deadlines (Part A recurring, Part B and C one-time)","Minimal cross-referencing (references one FAA AD and one Boeing service bulletin)","Clear applicability criteria (specific Boeing models and line numbers)","Simple conditional logic ('unless previously accomplished' clauses)","No nested exceptions or complex definitional sections"],"plain_english_summary":"This mandatory AD orders operators of Boeing 747-200/-300 (line nos. 1–720) to inspect and repair bolts at the front spar lower chord splice fitting in the wing centre section—after reports of fuel leaking into the forward cargo compartment, creating a serious fire risk. It requires recurring inspections and ultimately permanent repairs and secondary fuel-barrier checks by the stated deadline. This 4th amendment aligns the directive with the latest FAA requirements."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-64-amdt-4-wing-centre-section-front-spar-lower-chord-splice-fitting-bolts","history":"/api/acts/ad-b747-64-amdt-4-wing-centre-section-front-spar-lower-chord-splice-fitting-bolts/history","analysis":"/api/acts/ad-b747-64-amdt-4-wing-centre-section-front-spar-lower-chord-splice-fitting-bolts/analysis","conflicts":"/api/acts/ad-b747-64-amdt-4-wing-centre-section-front-spar-lower-chord-splice-fitting-bolts/conflicts","importantCases":"/api/acts/ad-b747-64-amdt-4-wing-centre-section-front-spar-lower-chord-splice-fitting-bolts/important-cases","documents":"/api/acts/ad-b747-64-amdt-4-wing-centre-section-front-spar-lower-chord-splice-fitting-bolts/documents"}}