{"id":"F2006B03078","name":"AD/B747/176 Amdt 1 - Centre Wing Tank Front Spar Web","slug":"ad-b747-176-amdt-1-centre-wing-tank-front-spar-web","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42437,"registerId":"commonwealth-F2006B03078-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/176 Amdt 1 - Centre Wing Tank Front Spar Web","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)  \n![](image.002.png)  \nBoeing 747 Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B747/176 and issues the following AD under subregulation 39.1 (1) of CAR 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\nAD/B747/176\n\nAmdt 1\n\n  \nCentre Wing Tank Front Spar Web 9/2000\n\nApplicability: Model 747-200, \\-300, and \\-400 series aircraft, line numbers up to and including 744.\n\nRequirement: Inspect in accordance with the technical requirements of FAA AD 2000-11-07 Amdt 39-11755.\n\nNote: Boeing Alert Service Bulletins 747-57A2298 Revision 1, Revision 2, and Revision 3 refer.\n\nCompliance: As specified in the Requirement document for the initial and repetitive inspection requirements, with a revised effective date of 7 September 2000.\n\nThis Amendment becomes effective on 7 September 2000.\n\nBackground: The FAA received reports of fatigue cracking of the front spar web of the centre wing tank. The actions specified by this Directive are intended to prevent the leakage of fuel into the forward cargo bay, as a result of the fatigue cracking, which could result in a potential fire hazard.\n\nAmendment 1 is issued in response to a new FAA AD which requires that the existing inspection be accomplished at a reduced threshold, and adds a requirement that the existing High Frequency Eddy Current inspection be accomplished on repaired areas. This action was prompted by reports of cracking in repaired areas of the front spar web and cracking of the front spar web on an aircraft that had accumulated fewer flight cycles than the currently required inspection threshold.\n\nThe original issue of this Airworthiness Directive became effective on 19 June 1997.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.003.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority Date 27 July 2000\n\n![](image.002.png)\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 9 August 2000.","sortOrder":0}],"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":4,"scope_assessment":{"changed":true,"description":"Amendment 1 tightens the original AD by reducing the inspection threshold and adding a requirement to perform HFEC inspections on repaired areas (Amendment 1; Background). The amendment revises inspection timing and expands the inspected scope compared with the original AD (original effective 19 June 1997; amendment effective 7 September 2000)."},"complexity_factors":["Cross-reference to external FAA AD 2000-11-07 and Boeing Alert Service Bulletins (Requirement; Note) — operators must obtain and follow separate technical documents.","Model- and line-number-limited applicability (Model 747-200/-300/-400, line numbers up to and including 744) (Applicability) — identification and tracking burden.","Reduced inspection threshold and added HFEC requirement on repaired areas (Amendment 1; Background) — increases inspection frequency and scope.","Initial and repetitive inspection scheduling tied to the Requirement document with a revised effective date (Compliance) — ongoing compliance planning.","Safety-critical structure (centre wing tank front spar web) implicated by fuel-leak/fire risk (Background) — stops-for-action and prioritisation pressures.","Regulatory enforcement by CASA delegate under subregulation 39.1(1) (preamble/signature) — limited administrative discretion in issuance, but technical content mandated by referenced FAA AD."],"plain_english_summary":"This Airworthiness Directive requires operators of Boeing 747-200/ -300/ -400 (line numbers up to 744) to inspect the centre wing tank front spar web per FAA AD 2000-11-07, including a reduced inspection threshold and added high-frequency eddy-current (HFEC) checks on repaired areas. CASA enforces the rule: aircraft operators bear the cost of inspections, repairs and repeated checks and must follow the FAA/Boeing technical instructions by the compliance dates specified (Requirement; Compliance; Applicability)."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment stays within the original scope of the 1997 directive. It tightens inspection thresholds and adds a requirement for repaired areas, but does not expand to new aircraft types, new structural components, or unrelated safety issues. The core purpose — preventing fuel leaks from centre wing tank fatigue cracks — remains unchanged."},"complexity_factors":["Short, single-purpose document (1 page) with clear structure","Only 3 defined sections (Applicability, Requirement, Compliance) plus Background","Single cross-reference to external technical document (FAA AD 2000-11-07 Amdt 39-11755)","No nested conditional logic or exceptions — requirements apply straightforwardly to listed aircraft models","Technical aviation terminology used but explained in context (e.g., 'spar web', 'High Frequency Eddy Current')","Amendment structure is simple: revokes previous AD, states what replaces it, gives effective date"],"plain_english_summary":"This safety order replaces an earlier directive and tightens inspection rules for the centre wing fuel tank front spar web on Boeing 747-200/300/400 series (line numbers up to 744). It requires earlier and more frequent inspections — including High Frequency Eddy Current checks of repaired areas — because fatigue cracks have been found that could allow fuel into the forward cargo bay and create a fire risk. Effective 7 September 2000."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-176-amdt-1-centre-wing-tank-front-spar-web","history":"/api/acts/ad-b747-176-amdt-1-centre-wing-tank-front-spar-web/history","analysis":"/api/acts/ad-b747-176-amdt-1-centre-wing-tank-front-spar-web/analysis","conflicts":"/api/acts/ad-b747-176-amdt-1-centre-wing-tank-front-spar-web/conflicts","importantCases":"/api/acts/ad-b747-176-amdt-1-centre-wing-tank-front-spar-web/important-cases","documents":"/api/acts/ad-b747-176-amdt-1-centre-wing-tank-front-spar-web/documents"}}