{"id":"F2006B03106","name":"AD/B747/207 Amdt 1 - Nacelle Diagonal Brace Steel Attachment Fittings","slug":"ad-b747-207-amdt-1-nacelle-diagonal-brace-steel-attachment-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42478,"registerId":"commonwealth-F2006B03106-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/207 Amdt 1 - Nacelle Diagonal Brace Steel Attachment Fittings","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nOn the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B747/207 and issues the following 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\nBoeing 747 Series Aeroplanes\n\nAD/B747/207\n\nAmdt 1\n\n  \n\nNacelle Diagonal Brace Steel Attachment Fittings\n\n  \n10/2004\n\nApplicability: Model 747 series aircraft equipped with General Electric Model CF6-45 or \\-50 engines, or Pratt & Whitney JT9D-3, -7, or -70 series engines, having steel attachment fittings of the diagonal brace to the nacelle struts.\n\nRequirement: Perform a detailed visual inspection in accordance with the technical requirements of FAA AD 2001-16-08 Amendment 39-12376.\n\nCompliance: As specified in the requirement document for the initial and repetitive inspections.\n\nThis Amendment becomes effective on 30 September 2004.\n\nBackground: The original issue of this AD was raised in response to a report of a fatigue crack in one of the steel attachment fittings of the diagonal brace to nacelle strut. At that time FAA AD 99-09-11 referred.\n\nSubsequent to this, the FAA released AD 2001-16-08 Amdt 39-12376 which superseded FAA AD 99-09-11. This amendment is issued as a result of the new FAA AD.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nDavid Villiers\n\nDelegate of the Civil Aviation Safety Authority 19 August 2004\n\n![](image.001.png)\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 8 September 2004.\n\n  \n\nPage 1 of 1","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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope — safety inspection of nacelle diagonal brace fittings on specific Boeing 747 models. It simply updates the technical reference to match a newer FAA directive, without expanding the types of aircraft covered or the nature of the safety action required."},"complexity_factors":["Very short document (1 page)","Only 3 substantive sections: Applicability, Requirement, and Compliance","No defined terms section — all technical terms are standard aviation vocabulary","Single cross-reference to an external FAA document (AD 2001-16-08) rather than internal legislative cross-referencing","No conditional logic or nested exceptions — straightforward mandatory inspection requirement","Clear, unambiguous compliance deadline (effective date specified)"],"plain_english_summary":"This CASA Airworthiness Directive mandates detailed visual inspections of steel attachment fittings that tie diagonal braces to engine nacelle struts on certain Boeing 747s with specified GE or Pratt & Whitney engines. It requires initial and recurring inspections following FAA AD 2001‑16‑08.\n\nThe AD amends and replaces the earlier 1999 directive because fatigue cracks were found; unchecked cracking could lead to engine-mount failure or engine separation, so operators must comply to ensure continued structural safety."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment does not broaden the AD’s safety scope. It revokes the prior CASA AD and replaces its technical reference to an earlier FAA AD with the newer FAA AD 2001-16-08. The underlying purpose—detecting and correcting fatigue cracking in the same steel attachment fittings—remains the same; the amendment simply aligns CASA’s requirement with the FAA's later directive rather than expanding the affected systems or imposing new categories of obligations."},"complexity_factors":["Short, single-purpose AD (1 page) with narrow applicability (specific Boeing 747 models with listed engine types and specific steel fittings).","Primary technical detail and all inspection intervals are delegated by reference to FAA AD 2001-16-08 (external cross-reference increases practical complexity).","No detailed definitions or alternative procedures in the CASA text—operators must consult the FAA AD for substantive instructions.","Simple conditional logic: applicability → perform inspection → comply with intervals; limited exceptions or nested conditions within the CASA AD itself.","Dependence on an external foreign authority document means tracking amendments or superseding actions by the FAA to remain compliant."],"plain_english_summary":"**What this instrument does (mechanics)\n\n- Revokes the earlier AD/B747/207 and issues an amended Airworthiness Directive (AD) that applies to Boeing 747 series aeroplanes that have certain engine types (General Electric CF6-45 or -50, or Pratt & Whitney JT9D-3, -7 or -70) and that have steel attachment fittings where the nacelle diagonal brace joins the nacelle struts. (See \"Applicability\".)\n- Requires operators to perform a detailed visual inspection of the steel attachment fittings of the diagonal brace to the nacelle struts. The inspection must be carried out in accordance with the technical instructions set out in FAA AD 2001-16-08 (this AD is referenced in the \"Requirement\" section).\n- Requires compliance with the initial and repetitive inspection intervals specified in the referenced FAA AD (see the \"Compliance\" section).\n- Becomes effective 30 September 2004.\n\nWhy the amendment was issued (official rationale)\n\n- The AD was issued because a fatigue crack was reported in one of the steel attachment fittings where a diagonal brace attaches to the nacelle strut (see \"Background\"). CASA initially relied on an earlier FAA AD; the FAA later superseded that earlier AD with FAA AD 2001-16-08. This amendment brings the CASA AD into alignment with the newer FAA AD.\n\nWho is affected and who pays\n\n- Aircraft operators (airlines, cargo operators) that operate the affected Boeing 747s must carry out the inspections and any corrective action. Maintenance organisations (MROs) that inspect and repair these aircraft will perform the work. The operators bear the direct costs (labour, possible replacement parts, and aircraft down-time).\n\nPractical effects and how it works in plain language\n\n- If you operate an affected 747 variant, you must follow the inspection instructions in FAA AD 2001-16-08 for the specific fittings named. That FAA AD sets out how to inspect (detailed visual) and when to inspect initially and thereafter. If you find cracking or other defects, you must take the corrective actions specified in the FAA AD. The CASA AD makes those FAA instructions mandatory in Australia by direct reference.\n\nTesting the official purpose-claim against costs, incentives and implementation risks\n\n- Claimed purpose: to detect and correct fatigue cracking in the steel attachment fittings so the fittings do not fail in service. The AD’s mechanism (mandatory inspections and corrective action) fits that purpose.\n- Who pays: operators incur inspection and repair costs and any aircraft downtime.\n- Incentives and trade-offs: regular mandated inspections increase safety margin but increase maintenance cost and possible aircraft out-of-service time. Operators may prefer to replace the fittings early rather than face repeated inspections if long-term cost or availability of parts makes that economical.\n- Compliance burden and discretion: the AD delegates the detailed technical method and intervals to the FAA AD, so the technical burden is in complying with that external document. CASA’s role is to require compliance, not to define the inspection method itself (see \"Requirement\").\n- Effects on private markets: MROs will capture the inspection work; larger operators with in-house heavy maintenance capability may find it cheaper to comply than smaller operators relying on external providers. There is no explicit restriction on who may perform the inspection beyond ordinary regulatory requirements for maintenance personnel.\n- Risks and limitations: the inspection required is a \"detailed visual inspection\". Visual inspection can detect surface cracking but may miss subsurface fatigue unless the FAA AD requires additional NDT (non‑destructive testing); operators must follow all technical steps in the FAA AD. Relying on an external (FAA) directive increases clarity on the technical fix but makes Australian compliance dependent on the content and future amendments of that FAA document.\n\nConcentrated benefits and diffuse costs\n\n- The immediate safety benefit is concentrated on the aircraft (operators and their passengers/crew) that avoid a potential in-service failure. The costs (inspection and repair) are borne by the relatively small group of operators of affected 747 variants.\n\nSummary (short)\n\n- This CASA amendment makes mandatory the detailed visual inspections and follow-up actions specified in FAA AD 2001-16-08 for certain Boeing 747 nacelle diagonal brace steel attachment fittings, in response to a reported fatigue crack. The technical requirements and inspection intervals are implemented by reference to the FAA AD, and operators must comply by the dates set out in that FAA AD."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-207-amdt-1-nacelle-diagonal-brace-steel-attachment-fittings","history":"/api/acts/ad-b747-207-amdt-1-nacelle-diagonal-brace-steel-attachment-fittings/history","analysis":"/api/acts/ad-b747-207-amdt-1-nacelle-diagonal-brace-steel-attachment-fittings/analysis","conflicts":"/api/acts/ad-b747-207-amdt-1-nacelle-diagonal-brace-steel-attachment-fittings/conflicts","importantCases":"/api/acts/ad-b747-207-amdt-1-nacelle-diagonal-brace-steel-attachment-fittings/important-cases","documents":"/api/acts/ad-b747-207-amdt-1-nacelle-diagonal-brace-steel-attachment-fittings/documents"}}