{"id":"F2006B03187","name":"AD/B747/293 - Aft Lower Lobe Cargo Door Cutout","slug":"ad-b747-293-aft-lower-lobe-cargo-door-cutout","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42559,"registerId":"commonwealth-F2006B03187-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\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\nBoeing 747 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/B747/293 Aft Lower Lobe Cargo Door Cu","sectionType":"part","heading":"AD/B747/293 Aft Lower Lobe Cargo Door Cutout 8/2003","content":"# AD/B747/293 Aft Lower Lobe Cargo Door Cutout 8/2003\n\nApplicability: Model 747 series aircraft, line numbers 1 through 1255.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 2003-10-06 Amdt 39-13151.\n\nNote: Boeing Service Bulletin 747-53A2448 Revision 1 refers.\n\nIf inspection reveals damage, accomplish repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis approved by a Boeing Company Designated Engineering Representative who has been authorised by the Manager, Seattle ACO, to make such findings.\n\nCompliance: As specified in the Requirement document, with a revised effective date of 7 August 2003.\n\nThis Airworthiness Directive becomes effective on 7 August 2003.\n\nBackground: The manufacturer received numerous reports of cracks in the forward and aft upper corners of the aft lower lobe cargo door cutout. This Directive requires inspections to detect cracking of the skin, bear strap, and sill chord of the aft lower lobe cargo door cutout, which undetected, could lead to reduced structural integrity of the cutout and result in rapid depressurisation of the aircraft.\n\n![Signature of David Punshon, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nDavid Punshon\n\nDelegate of the Civil Aviation Safety Authority 27 June 2003\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD remains focused on the original, stated safety issue: inspection and repair of cracks around the aft lower lobe cargo door cutout on specified Boeing 747 airframes. It cross-references the FAA AD and a Boeing service bulletin for technical detail but does not broaden the set of affected aircraft, the types of actions required, or the approval paths beyond those referenced. The revised effective date noted in Compliance changes timing, not scope."},"complexity_factors":["Single narrow safety topic (aft lower lobe cargo door cutout cracking) — limited subject matter","Applicability limited to Boeing 747 line numbers 1–1255 (simple scope filter)","Direct cross-reference to FAA AD 2003-10-06 for detailed technical and compliance instructions (external dependency increases complexity)","Reference to Boeing Service Bulletin 747-53A2448 Rev 1 (additional external document)","Conditional repair approval paths: either FAA Seattle ACO approval or Boeing DER authorised by Seattle ACO (two approval routes to manage)","No lengthy exceptions or nested conditional clauses within the AD text itself (low internal nesting)","Short document with a single compliance effective date (7 August 2003) — few timing permutations"],"plain_english_summary":"**What this directive does (mechanically):**\n\n- Requires operators of certain Boeing 747 aeroplanes to carry out inspections of the aft lower lobe cargo door cutout for cracking, and to repair any damage found, following the technical instructions set out in FAA Airworthiness Directive 2003-10-06 (see \"Requirement\"). (Applicability, Requirement)\n- If an inspection finds damage, repairs must be carried out either under a method approved by the Manager, Seattle Aircraft Certification Office (FAA), or using data that meets the type certification basis and that has been approved by a Boeing Designated Engineering Representative (DER) authorised by the Seattle ACO. (Requirement)\n- The AD applies to Boeing Model 747 series with line numbers 1 through 1255. (Applicability)\n- Compliance must follow the timing and procedures in the referenced FAA AD; this Australian AD becomes effective 7 August 2003. (Compliance)\n\n**Who is affected:**\n\n- Owners and operators of Boeing 747 aeroplanes with line numbers 1–1255. (Applicability)\n- Maintenance organisations and engineers who perform structural inspections and repairs on those aircraft. (Requirement)\n\n**What parts are inspected (in plain language):**\n\n- The skin (outer metal surface) and primary structural pieces around the aft lower lobe cargo door cutout — specifically the bear strap and sill chord at the forward and aft upper corners of the cutout. These are structural elements that carry loads around the cargo door opening. (Background, Requirement)\n\n**Why it matters (stated purpose and mechanical risk):**\n\n- The manufacturer received multiple reports of cracks in the forward and aft upper corners of the aft lower lobe cargo door cutout. If those cracks go undetected, the structural integrity of the door cutout could be reduced and that could lead to rapid depressurisation of the aircraft. The AD’s stated purpose is to detect and repair cracking before it can cause that outcome. (Background)\n\n**Who pays and who decides:**\n\n- Operators pay for the inspections, any necessary repairs, and any aircraft downtime while work is done. (Requirement, Compliance)\n- The Civil Aviation Safety Authority (CASA) delegate issued the AD, but the technical instructions and acceptance of repair methods are referenced to the FAA Seattle ACO or an authorised Boeing DER. That means technical approval authority for repair methods rests with those FAA offices/authorised representatives. (Requirement)\n\n**Behaviour changes required of operators and maintainers:**\n\n- Schedule and perform the inspections required by FAA AD 2003-10-06 for the specified aircraft.\n- If cracks or damage are found, obtain and follow an approved repair method from the Seattle ACO or an appropriately authorised Boeing DER; document compliance as required by regulatory/maintenance records. (Requirement)\n\n**Compliance burden and costs:**\n\n- Direct costs: labour and materials for inspections and repairs. If damage requires structural repair, costs can be material- and labour-intensive.\n- Indirect costs: aircraft downtime (lost revenue), logistics to move aircraft to suitably equipped maintenance facilities, potential parts lead-times.\n\n**Implementation, discretion and risk:**\n\n- The AD relies on technical instructions from a foreign regulator (FAA AD 2003-10-06) and on FAA/Aircraft Certification Office approval for repairs. That introduces coordination risk for operators and maintenance providers who must obtain FAA or Boeing DER approvals when damage is found. (Requirement)\n- Because the AD cross-references external documents (FAA AD and a Boeing Service Bulletin), failure to follow or misinterpret those documents could lead to inconsistent compliance. (Note)\n\n**Trade-offs and opportunity costs:**\n\n- The AD imposes inspection and repair costs on operators in exchange for reduced risk of structural failure/rapid depressurisation. Operators must weigh the expense and downtime against safety risk; from a mechanical standpoint the AD reduces technical uncertainty by prescribing inspection and approved repair routes. (Background, Requirement)\n\n**Source attribution and testing the claimed purpose:**\n\n- The directive states its purpose is to detect cracking that could lead to rapid depressurisation (Background). Mechanically, mandatory inspection and repair is a standard regulatory instrument to find and correct fatigue or crack growth before failure. The practical costs are borne by operators through maintenance work and potential downtime, while approval authority for repairs is concentrated with the Seattle ACO or an authorised Boeing DER. (Background, Requirement)\n\n**Key references in the AD text:**\n\n- Applicability: Model 747 line numbers 1–1255. (Applicability)\n- Requirement: Follow FAA AD 2003-10-06. (Requirement)\n- Note: Boeing Service Bulletin 747-53A2448 Rev 1 is referred to. (Note)\n- Compliance: Effective date and timing follow the Requirement document; AD effective 7 August 2003. (Compliance)\n"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, targeted airworthiness directive addressing a specific structural safety issue (cracking in cargo door cutouts). It has not expanded beyond its original purpose of mandating inspections and repairs for this particular unsafe condition."},"complexity_factors":["Very short document (approximately 250 words)","Only 3 defined structural terms (bear strap, sill chord, cutout) with contextual explanations","Single cross-reference to FAA AD 2003-10-06 and Boeing Service Bulletin 747-53A2448","Simple conditional logic: if inspection reveals damage → accomplish repair per approved method","No nested exceptions or complex compliance calculations","Clear, linear structure: Applicability → Requirement → Compliance → Background"],"plain_english_summary":"This is a safety order (called an Airworthiness Directive or AD) issued by Australia's aviation safety regulator (CASA) that applies to Boeing 747 aircraft. It requires airlines and aircraft operators to inspect specific parts of the cargo door area on these planes for cracks. The concern is that cracks in the skin, bear strap (a reinforcing piece), and sill chord (a structural support) around the aft lower lobe cargo door could weaken the aircraft structure and potentially cause sudden loss of cabin pressure. If cracks are found, repairs must be done using methods approved by the US aviation authority (FAA) or by Boeing engineers authorised by the FAA. The directive takes effect on 7 August 2003 and applies to Boeing 747s with line numbers 1 through 1255."},"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-b747-293-aft-lower-lobe-cargo-door-cutout","history":"/api/acts/ad-b747-293-aft-lower-lobe-cargo-door-cutout/history","analysis":"/api/acts/ad-b747-293-aft-lower-lobe-cargo-door-cutout/analysis","conflicts":"/api/acts/ad-b747-293-aft-lower-lobe-cargo-door-cutout/conflicts","importantCases":"/api/acts/ad-b747-293-aft-lower-lobe-cargo-door-cutout/important-cases","documents":"/api/acts/ad-b747-293-aft-lower-lobe-cargo-door-cutout/documents"}}