{"id":"F2006B03410","name":"AD/B767/56 - Vertical Stabiliser","slug":"ad-b767-56-vertical-stabiliser","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42951,"registerId":"commonwealth-F2006B03410-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B767/56 - Vertical Stabiliser","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 767 Series Aeroplanes\n\n \n\nAD/B767/56 Vertical Stabiliser 8/91\n\nApplicability: Model 767 series with line numbers 300 through 307.\n\n \n\nRequirement: Action IAW the Technical Requirements of FAA AD 91-10-09 Amdt 39-6993.\n\n \n\nNote: Boeing SB 767-55A0007 refers.\n\n \n\nCompliance: As specified in the Requirement Document.\n\n \n\nBackground:  Modification of the vertical stabilizer forward closure rib by installation of a lower plate and a panel assembly over lightening and access holes, was not incorporated during production on certain aircraft.\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":3,"scope_assessment":{"changed":false,"description":"The AD confines its effect to Boeing 767 aeroplanes with line numbers 300–307 and requires them to be modified in accordance with the FAA AD 91-10-09 and the referenced Boeing service bulletin. The schedule entry does not broaden or narrow that stated applicability or the referenced technical requirement in this text; it implements the FAA technical requirement for the identified aircraft rather than changing its scope. (Applicability; Requirement; Note)"},"complexity_factors":["Cross-reference to an external FAA AD for the technical requirements (Requirement)","Reference to a manufacturer service bulletin (Note) rather than embedding technical steps","Limited applicability by specific line numbers (Applicability) which narrows scope but requires per-aircraft verification","Technical/maintenance work (structural modification) requiring parts, skilled labour and aircraft downtime (Background)","No technical detail, timing, or cost information in the AD text itself (Compliance)"],"plain_english_summary":"What this instrument does\n\n- This Airworthiness Directive (AD) requires certain Boeing 767 aeroplanes to have a modification carried out on the vertical stabiliser forward closure rib. The modification is the installation of a lower plate and a panel assembly over lightening and access holes. (Background)\n- The AD applies only to Boeing 767 series aeroplanes with line numbers 300 through 307. (Applicability)\n- The technical steps and standards to carry out the modification are set out by reference to the FAA Airworthiness Directive 91-10-09 Amendment 39-6993; a Boeing Service Bulletin (SB 767-55A0007) is noted as a reference. The AD requires action “in accordance with” that FAA document. (Requirement; Note)\n- Compliance must be achieved as specified in the Requirement Document (that is, by following the referenced FAA AD). (Compliance)\n\nWho is affected and who decides\n\n- Affected parties: the owners/operators of the specific Boeing 767 aircraft listed by line number (300–307). (Applicability)\n- Decision-making: the Civil Aviation Safety Authority (CASA) issues and enforces this AD under the Civil Aviation Regulations; the AD delegates the detailed technical method to the FAA AD and to Boeing’s service information. (Requirement; Note)\n\nWho pays and what behaviour changes\n\n- Who pays: operators of the affected aeroplanes will incur the costs of parts, materials, labour and any aircraft downtime needed to perform the modification. (Applicability; Background; Requirement)\n- Behaviour change required: affected operators must schedule and carry out the specified structural modification on each affected aircraft and document compliance per the referenced Requirement Document. (Requirement; Compliance)\n\nMechanics and implementation\n\n- The AD does not reproduce detailed instructions in this text; it requires compliance by following the FAA AD (91-10-09) and associated Boeing service information. This means operators must obtain and implement those technical documents to complete the work. (Requirement; Note)\n- The AD’s text does not state timings, man-hour estimates, or supply arrangements in this schedule entry; those specifics are in the referenced FAA AD / Boeing SB. (Requirement; Compliance)\n\nIncentives, costs and trade-offs (source-grounded)\n\n- Incentive to comply: regulatory obligation to satisfy the AD and avoid regulatory enforcement action. (Requirement; Compliance)\n- Concentrated benefits: each modified aeroplane receives the structural change described in the Background; the benefit (as framed in this document) accrues to those specific aircraft. (Background)\n- Concentrated costs: the operators of the listed aircraft bear the direct costs (parts, labour, downtime). (Applicability; Background)\n- Decision and discretion: the AD fixes the obligation while leaving the technical means to the FAA AD and Boeing SB; operators retain limited operational discretion about scheduling and how they source parts and maintenance resources, subject to meeting the Requirement Document. (Requirement; Note; Compliance)\n\nPractical implementation risks and administrative burden (source-grounded)\n\n- Administrative/operational burden: operators must obtain the FAA AD and Boeing SB, arrange maintenance to the required standards, and record compliance as required by CASA and the referenced documents. (Requirement; Note; Compliance)\n- Implementation risks signalled by the AD’s form: the AD cross-references external technical documents rather than setting out step-by-step measures here, so failure to obtain or correctly follow the external documents would be the principal compliance risk. (Requirement; Note)\n\nWhere to look for the technical detail\n\n- The FAA AD 91-10-09 Amendment 39-6993 contains the Technical Requirements that must be followed. Boeing Service Bulletin 767-55A0007 is referenced and will contain the manufacturer guidance for the structural modification. (Requirement; Note)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive targeting a specific manufacturing defect on a limited production run of aircraft. It has not expanded beyond its original purpose of mandating a specific structural modification."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 1 defined applicability criterion (line numbers 300–307)","Single requirement referencing external technical document (FAA AD 91-10-09)","No nested exceptions or conditional logic","No internal cross-references within the instrument itself","Technical content is incorporated by reference rather than spelled out in the directive"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific Boeing 767 aircraft.\n\n**What it does:**\n- Requires owners/operators of certain Boeing 767 planes (specifically those with production line numbers 300–307) to carry out a specific modification to the **vertical stabiliser** (the tall fin at the back of the aircraft).\n- The fix involves installing a lower plate and panel assembly over certain holes in the forward closure rib of the vertical stabiliser. This was supposed to be done during manufacturing but was missed on these particular aircraft.\n\n**Who it affects:**\n- Operators of Boeing 767 aircraft with line numbers 300–307.\n- Maintenance organisations servicing these specific aircraft.\n\n**Why it matters:**\n- The missing modification could affect the structural integrity of the vertical stabiliser, which is critical for aircraft control and stability. The directive ensures these aircraft meet safety standards by mandating the retrofit.\n- Compliance is mandatory \"as specified in the Requirement Document\" (the referenced FAA directive).\n\n**Key references:**\n- Follows **FAA AD 91-10-09** (the US aviation safety regulator's equivalent order).\n- **Boeing Service Bulletin 767-55A0007** provides technical instructions for the modification."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-56-vertical-stabiliser","history":"/api/acts/ad-b767-56-vertical-stabiliser/history","analysis":"/api/acts/ad-b767-56-vertical-stabiliser/analysis","conflicts":"/api/acts/ad-b767-56-vertical-stabiliser/conflicts","importantCases":"/api/acts/ad-b767-56-vertical-stabiliser/important-cases","documents":"/api/acts/ad-b767-56-vertical-stabiliser/documents"}}