{"id":"F2006B02756","name":"AD/B727/54 - Landing Gear Forward Trunnion Support Special Stud - Replacement","slug":"ad-b727-54-landing-gear-forward-trunnion-support-special-stud-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42098,"registerId":"commonwealth-F2006B02756-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/54 - Landing Gear Forward Trunnion Support Special Stud - Replacement","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 727 Series Aeroplanes\n\n \n\nAD/B727/54 Landing Gear Forward Trunnion Support\n\nSpecial Stud - Replacement\n\n\n9/67\n\n \n\nApplicability: All models. Document: Boeing SB No. 57-74. Compliance: Forthwith.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive from 1967 addressing one specific mechanical component. It has not expanded beyond its original narrow purpose of mandating replacement of a defective landing gear part."},"complexity_factors":["Extremely short document — only 4 substantive lines of regulatory text","No defined terms section — all terminology refers to external Boeing documentation","No conditional logic or exceptions — simple universal applicability ('All models')","Single compliance requirement with no alternative methods or phased implementation","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nOrders the **replacement of a specific part** on Boeing 727 aircraft — the \"special stud\" in the forward trunnion support of the landing gear. A trunnion is a pivot point that helps the landing gear extend and retract.\n\n**Who it affects:**\n- **All Boeing 727 models** registered in Australia\n- Aircraft operators, maintenance engineers, and owners responsible for keeping these planes airworthy\n\n**Why it matters:**\nLanding gear failures are catastrophic. This directive addresses a known safety issue with a specific component that could fail, potentially causing the landing gear to collapse during takeoff or landing. The word \"Forthwith\" means **immediate compliance is required** — there's no grace period.\n\n**Key details:**\n- **Document reference:** Boeing Service Bulletin No. 57-74 (the manufacturer's official repair instructions)\n- **Compliance:** Immediate (\"Forthwith\")\n- **Date issued:** September 1967 (this is a historical directive)"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text supplied sets a focused requirement (replace the special stud) applied to all Boeing 727 models and requires immediate compliance, with technical instructions referenced to Boeing SB No. 57-74. There is no material in the supplied text indicating a change in scope from an earlier or original intent; the directive language is concise and its scope is clear in the document as provided (see title, \"Applicability: All models.\", and \"Compliance: Forthwith.\")."},"complexity_factors":["Narrow, specific technical subject matter (replacement of a single component) reduces legal complexity.","Mandatory immediate compliance (\"Compliance: Forthwith\") increases operational urgency despite simple wording.","Delegation of technical procedure to an external manufacturer document (\"Document: Boeing SB No. 57-74\") requires cross-reference to non-statutory material for implementation.","Lack of procedural detail in the text (no enforcement, alternative method, or compliance record-keeping details) shifts interpretive burden to regulators and maintainers.","Applicability to \"All models\" broadens who must act, increasing administrative coordination for operators with multiple variants."],"plain_english_summary":"The Civil Aviation Safety Authority requires immediate replacement of a \"special stud\" on the landing-gear forward trunnion support of all Boeing 727 series aeroplanes. Operators and owners must arrange the work forthwith, following Boeing Service Bulletin No. 57-74 for technical instructions.  \n\nCompliance is mandatory and immediate, so operators bear parts, labour and downtime costs; the AD delegates technical method to Boeing’s service bulletin and contains no alternate compliance or cost-allocation provisions."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-54-landing-gear-forward-trunnion-support-special-stud-replacement","history":"/api/acts/ad-b727-54-landing-gear-forward-trunnion-support-special-stud-replacement/history","analysis":"/api/acts/ad-b727-54-landing-gear-forward-trunnion-support-special-stud-replacement/analysis","conflicts":"/api/acts/ad-b727-54-landing-gear-forward-trunnion-support-special-stud-replacement/conflicts","importantCases":"/api/acts/ad-b727-54-landing-gear-forward-trunnion-support-special-stud-replacement/important-cases","documents":"/api/acts/ad-b727-54-landing-gear-forward-trunnion-support-special-stud-replacement/documents"}}