{"id":"F2006B02754","name":"AD/B727/52 - Horizontal Stabilizer Trailing Edge Closure Rib Inboard Terminal Fitting - Inspection","slug":"ad-b727-52-horizontal-stabilizer-trailing-edge-closure-rib-inboard-terminal-fitting-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42096,"registerId":"commonwealth-F2006B02754-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/52 - Horizontal Stabilizer Trailing Edge Closure Rib Inboard Terminal Fitting - 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 727 Series Aeroplanes\n\n \n\nAD/B727/52 Horizontal Stabilizer Trailing Edge Closure\n\nRib Inboard Terminal Fitting - Inspection\n\nApplicability: All models. Document: Boeing SB No. 55-35. 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\n\n7/67\n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1967 (indicated by '7/67' at bottom). It addresses one specific safety concern on one aircraft type. There is no evidence of scope creep — it does exactly what it says on the tin: mandates inspection of one specific part."},"complexity_factors":["Extremely short document (approximately 150 words)","Only one substantive requirement (inspection)","Single cross-reference to Boeing Service Bulletin 55-35","No defined terms section","No conditional logic or exceptions","Simple applicability statement ('All models')","Straightforward compliance deadline ('forthwith')","Standardised AD format with minimal variation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:**\nThis directive requires an **inspection of a specific part** on Boeing 727 aircraft — the \"Horizontal Stabilizer Trailing Edge Closure Rib Inboard Terminal Fitting.\" In plain terms, this is a structural component near the tail of the plane that helps control the aircraft's pitch (up and down movement).\n\n**Who it affects:**\n- **All Boeing 727 aircraft** (all models)\n- **Operators and owners** of these planes\n- **Maintenance engineers** responsible for keeping these aircraft airworthy\n\n**What must be done:**\n- Inspect the specified fitting following the procedures in **Boeing Service Bulletin No. 55-35**\n- Do this **\"forthwith\"** — meaning immediately, without delay\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. If this part fails, it could compromise the aircraft's structural integrity or control surfaces, potentially leading to loss of control. Compliance is mandatory — you cannot legally fly the aircraft until this inspection is done."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD applies to all Boeing 727 models and requires inspection in accordance with Boeing SB No. 55-35 to be done forthwith. The published text does not indicate any narrowing or expansion of scope beyond that language; it sets a single, immediate inspection obligation for the entire model series. (Applicability: All models; Document: Boeing SB No. 55-35; Compliance: Forthwith)"},"complexity_factors":["Single, narrowly specified action: inspection of a named fitting (low procedural complexity).","Applicability to all Boeing 727 models increases the population of affected aircraft but does not add procedural complexity. (Applicability: All models)","Technical procedure and any remedial actions are delegated to an external document (Boeing SB No. 55-35), so the AD itself is short but depends on another document for technical detail. (Document: Boeing SB No. 55-35)","Immediate compliance requirement (\"forthwith\") creates scheduling and operational pressure for implementers. (Compliance: Forthwith)","AD text provides no detailed inspection steps or tolerance limits, leaving interpretation and execution to maintenance organisations following the referenced SB. (Document: Boeing SB No. 55-35)"],"plain_english_summary":"What this directive does (mechanical change)\n\n- The Civil Aviation Safety Authority (CASA) requires an inspection of the horizontal stabilizer trailing edge closure rib inboard terminal fitting on Boeing 727 series aeroplanes. (Header: PART 39 - 105; AD title)\n- The inspection must be carried out in accordance with Boeing Service Bulletin No. 55-35. (Document: Boeing SB No. 55-35)\n- The requirement applies to all models of the Boeing 727 series and must be carried out forthwith. (Applicability: All models; Compliance: Forthwith)\n\nWho this affects\n\n- Aircraft operators and owners of any Boeing 727 model are required to arrange the inspection. (Applicability: All models)\n- Organisations that perform maintenance on Boeing 727 aeroplanes will be engaged to carry out the inspection to the Boeing service bulletin standard. (Document: Boeing SB No. 55-35)\n- The regulator (CASA) is the issuing authority and sets the compliance obligation. (Header: Civil Aviation Safety Authority; PART 39 - 105)\n\nWhy it matters (stated purpose and practical implications)\n\n- Stated purpose: the AD requires inspection of a specific terminal fitting (the horizontal stabilizer trailing edge closure rib inboard terminal fitting) by reference to Boeing SB No. 55-35. The AD text itself does not set out technical steps or remediation actions; it points operators to the Boeing service bulletin for the inspection procedure. (Document: Boeing SB No. 55-35)\n\nPractical effects, costs and incentives\n\n- Who pays: operators/owners bear the direct costs of obtaining the Boeing service bulletin (if not already held), performing the inspection, and any follow-on maintenance or repair work found necessary. (Applicability: All models; Document: Boeing SB No. 55-35)\n- Timing and operational impact: the instruction to comply \"forthwith\" requires near-immediate scheduling of inspection, which can create short-term operational disruption or aircraft downtime while the work is done. (Compliance: Forthwith)\n- Compliance burden and information reliance: the AD delegates technical detail to Boeing SB No. 55-35; operators must source and follow that document to meet the AD. The AD does not itself describe the inspection technique or corrective steps. (Document: Boeing SB No. 55-35)\n- Regulator discretion: CASA, under the Civil Aviation Regulations (Part 39 - 105), has issued the AD and set the applicability and timing; the AD leaves technical implementation to the referenced service bulletin. (Header: PART 39 - 105; Document: Boeing SB No. 55-35)\n\nTrade-offs and implementation risks (mechanical, administrative)\n\n- Immediate inspection reduces the time window in which an undetected issue could persist, but it requires operators to reallocate maintenance capacity promptly. (Compliance: Forthwith)\n- Because the AD refers to an external service bulletin for procedure, differences in interpretation or availability of the bulletin could affect consistent implementation across operators. (Document: Boeing SB No. 55-35)\n\nSummary statement\n\n- In short: CASA requires that all Boeing 727 aeroplanes have the horizontal stabilizer trailing edge closure rib inboard terminal fitting inspected immediately, using Boeing Service Bulletin No. 55-35 as the procedural reference. Operators must arrange and pay for the inspection and any subsequent work required to comply. (Applicability: All models; Document: Boeing SB No. 55-35; Compliance: Forthwith)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-52-horizontal-stabilizer-trailing-edge-closure-rib-inboard-terminal-fitting-inspection","history":"/api/acts/ad-b727-52-horizontal-stabilizer-trailing-edge-closure-rib-inboard-terminal-fitting-inspection/history","analysis":"/api/acts/ad-b727-52-horizontal-stabilizer-trailing-edge-closure-rib-inboard-terminal-fitting-inspection/analysis","conflicts":"/api/acts/ad-b727-52-horizontal-stabilizer-trailing-edge-closure-rib-inboard-terminal-fitting-inspection/conflicts","importantCases":"/api/acts/ad-b727-52-horizontal-stabilizer-trailing-edge-closure-rib-inboard-terminal-fitting-inspection/important-cases","documents":"/api/acts/ad-b727-52-horizontal-stabilizer-trailing-edge-closure-rib-inboard-terminal-fitting-inspection/documents"}}