{"id":"F2006B03000","name":"AD/B747/10 Amdt 1 - Pressurisation Outflow Valves - Inspection","slug":"ad-b747-10-amdt-1-pressurisation-outflow-valves-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42359,"registerId":"commonwealth-F2006B03000-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/10 Amdt 1 - Pressurisation Outflow Valves - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Boeing 747 Series Aeroplanes\n\n \n\nAD/B747/10\n\nAmdt 1\n\n\nPressurisation Outflow Valves - Inspection 11/78\n\n \n\nApplicability: All models not incorporating Hamilton Standard SB No. 21-114, Revision 1. Document:               FAA AD 78-08-04, Amdt. 39-3187 (Boeing SB No. 747-21-2139, Rev. 1 refers). Compliance:               As detailed in Requirement Document.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This instrument is labelled Amendment 1 to AD/B747/10 (AD/B747/10 Amdt 1), indicating it modifies an earlier AD. The excerpted text shows the current applicability (exempting aircraft that have incorporated Hamilton Standard SB No. 21-114, Rev. 1) and references the FAA AD and Boeing Service Bulletin as the technical basis. The AD text provided does not include the original AD text or a summary of the alterations, so the precise nature and extent of the change from the original AD cannot be determined from this extract alone."},"complexity_factors":["References to external documents (FAA AD 78-08-04, Amdt. 39-3187; Boeing SB No. 747-21-2139 Rev. 1) rather than including procedural detail in the AD itself","Applicability conditional on incorporation of a specific service bulletin (Hamilton Standard SB No. 21-114, Rev. 1) requires operators to verify modification status","Compliance is specified only as \"As detailed in Requirement Document,\" creating dependence on an external Requirement Document whose contents are not reproduced here","Operational impacts (scheduling, labour, potential aircraft downtime) are not quantified in the text, requiring operators to estimate costs and plan implementation","Potential supply/contracting implications (demand for the named service bulletin/modification) introduce commercial considerations beyond pure technical compliance"],"plain_english_summary":"What this instrument does (mechanically)\n\n- This is Airworthiness Directive AD/B747/10 Amendment 1, titled \"Pressurisation Outflow Valves - Inspection\" (11/78). It requires inspection of the pressurisation outflow valves on Boeing 747 series aeroplanes. [AD/B747/10 Amdt 1]\n- The directive applies to \"All models not incorporating Hamilton Standard SB No. 21-114, Revision 1.\" That means any 747 that has not had that specific Hamilton Standard service bulletin modification must comply. [Applicability]\n- The AD points to external technical documents for the exact inspection procedures: it references FAA AD 78-08-04, Amdt. 39-3187 and Boeing Service Bulletin No. 747-21-2139, Revision 1, and states compliance must be carried out \"As detailed in Requirement Document.\" The AD itself does not reproduce the step‑by‑step tasks. [Document] [Compliance]\n\nWho it affects\n\n- Aircraft operators/airlines who operate Boeing 747 variants that have not incorporated Hamilton Standard SB No. 21-114, Revision 1. [Applicability]\n- Maintenance organisations and engineers who must perform the inspections and any corrective work specified in the referenced Requirement Document. [Compliance]\n- The Civil Aviation Safety Authority (CASA) is the issuer and enforcer of the AD in the Commonwealth of Australia framework. [header information]\n\nWhy it matters (stated purpose and practical implications)\n\n- The title and classification as an airworthiness directive indicate the stated purpose is to address an identified hazard or airworthiness concern with pressurisation outflow valves by mandating inspection. The AD relies on FAA and Boeing technical material for the required actions. [AD/B747/10 Amdt 1] [Document]\n\nPractical effects, incentives and trade‑offs\n\n- Who pays: Operators bear direct costs — time, labour and parts for inspections and any repairs. Maintenance organisations incur labour and scheduling costs. [Applicability] [Compliance]\n- Who decides: CASA issues the AD and requires compliance; operators decide how to schedule inspections and whether to adopt the Hamilton Standard SB (which, if incorporated, removes applicability). [header information] [Applicability]\n- Compliance burden: The AD does not include the detailed inspection steps in its text; operators must obtain and follow the referenced FAA AD, Boeing Service Bulletin and the Requirement Document. That creates administrative and logistical steps to source and implement the required documents. [Document] [Compliance]\n- Implementation risk: Because the AD points to external documents for procedures and standards, failure to obtain or correctly apply those documents increases the risk of inconsistent compliance. The AD’s text does not enumerate timeframes or exact tasks within the excerpt provided. [Document] [Compliance]\n- Behavioural substitution: Operators may choose to incorporate Hamilton Standard SB No. 21-114, Revision 1 to remove the aircraft from the AD’s applicability, which creates a concrete demand for that modification. The AD therefore creates an incentive to adopt the specific modification it references. [Applicability]\n- Concentrated benefits and diffuse costs: The exemption for aircraft that have incorporated a named service bulletin concentrates the commercial benefit of exemption on those who have installed that SB (and on the supplier of that SB). The costs of inspections are borne by the operators required to inspect. [Applicability] [Document]\n\nLimits of what this AD text establishes\n\n- The AD excerpted here sets the legal requirement to inspect but does not include the inspection procedures, intervals or corrective-action detail; those are contained in the referenced FAA AD/Boeing Service Bulletin and the Requirement Document. Implementing agents must consult those documents to know exactly what to do. [Document] [Compliance]\n\nCitation of source elements used: title and AD identifier (AD/B747/10 Amdt 1), Applicability clause, Document references (FAA AD 78-08-04 Amdt. 39-3187; Boeing SB No. 747-21-2139 Rev. 1), and the Compliance statement (\"As detailed in Requirement Document\")."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a specific airworthiness directive (AD) with a narrow, technical scope focused solely on inspection of pressurisation outflow valves on Boeing 747 aircraft. It represents the original intended purpose of such directives: targeted safety interventions for specific aircraft systems."},"complexity_factors":["Very short document (approximately 200 words)","Only 3 defined elements: applicability criteria, reference document, and compliance requirement","No nested conditional logic or exceptions","Single purpose: mandate inspection of specific aircraft component","No cross-references to other legislation sections","Straightforward structure: title, applicability, document reference, compliance"],"plain_english_summary":"This is a **safety directive for Boeing 747 aircraft** that requires inspections of pressurisation outflow valves.\n\n**What it does:**\n- Mandates that airlines and aircraft operators inspect the pressurisation outflow valves on certain Boeing 747 models\n- Applies specifically to planes that haven't been modified according to a particular Hamilton Standard service bulletin (SB No. 21-114, Revision 1)\n\n**Who it affects:**\n- Owners and operators of Boeing 747 aircraft\n- Maintenance organisations servicing these planes\n- The Civil Aviation Safety Authority (CASA), which enforces these rules\n\n**Why it matters:**\nPressurisation outflow valves control how air escapes from the cabin to maintain safe pressure at high altitudes. If these valves fail, it could lead to:\n- Loss of cabin pressure\n- Potential emergency situations\n- Risk to passenger and crew safety\n\nThe directive references an American Federal Aviation Administration (FAA) safety document (AD 78-08-04), showing Australia adopting international safety standards for aircraft maintenance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-10-amdt-1-pressurisation-outflow-valves-inspection","history":"/api/acts/ad-b747-10-amdt-1-pressurisation-outflow-valves-inspection/history","analysis":"/api/acts/ad-b747-10-amdt-1-pressurisation-outflow-valves-inspection/analysis","conflicts":"/api/acts/ad-b747-10-amdt-1-pressurisation-outflow-valves-inspection/conflicts","importantCases":"/api/acts/ad-b747-10-amdt-1-pressurisation-outflow-valves-inspection/important-cases","documents":"/api/acts/ad-b747-10-amdt-1-pressurisation-outflow-valves-inspection/documents"}}