{"id":"F2006B10387","name":"AD/HS 125/109 - MLG Sidestay Centre Pivot Attach Nut","slug":"ad-hs-125-109-mlg-sidestay-centre-pivot-attach-nut","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116039,"registerId":"commonwealth-F2006B10387-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/109 - MLG Sidestay Centre Pivot Attach Nut","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)  British Aerospace BAe 125 Series Aeroplanes\n\n \n\nAD/HS 125/109 MLG Sidestay Centre Pivot Attach Nut 9/90\n\nDM\n\nThis AD contents has been removed from the listing because the aircraft model is not currently on the register.\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":1,"scope_assessment":{"changed":false,"description":"Not applicable — this is a current administrative record of a removed directive, not a substantive legislative amendment. The original scope (BAe 125 landing gear hardware) remains unchanged; the directive has simply been deactivated because the regulated population (aircraft) no longer exists in Australia."},"complexity_factors":["Document is essentially a placeholder/removal notice (3 sentences of substance)","No operative provisions currently in force","No defined terms, cross-references, or conditional logic","Single administrative action: removal from register due to zero affected aircraft"],"plain_english_summary":"This document is an **Airworthiness Directive (AD)** — a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA). \n\n**What it does:**\n- Originally required inspection or replacement of a specific nut on the main landing gear (MLG) \"sidestay centre pivot\" of British Aerospace BAe 125 series aircraft.\n- The \"sidestay\" is a structural strut that helps hold the landing gear in place when extended.\n\n**Current status:**\n- **The directive has been removed from active listing** because no BAe 125 aircraft are currently registered in Australia.\n\n**Who it affects:**\n- Previously affected owners and operators of BAe 125 series business jets.\n- Currently affects no one, as the aircraft type is not on the Australian register.\n\n**Why it matters:**\n- Airworthiness Directives are legally enforceable safety orders. When active, compliance is mandatory.\n- This shows how aviation safety regulation adapts — when aircraft types leave the fleet, associated directives are administratively removed rather than left as dead law."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The schedule entry for AD/HS 125/109 has been removed from the Australian public listing because the British Aerospace BAe 125 model is not on the Australian aircraft register. Mechanically, this reduces the scope of the schedule's application in Australia to zero registered aircraft of that type; it does not, in this entry, provide or replicate the original AD's technical requirements or state whether they have been rescinded elsewhere."},"complexity_factors":["Document is a short administrative schedule note with minimal text.","Effect depends on an external fact (whether the aircraft model is on the Australian register) rather than on technical or procedural detail within the entry.","No technical content of the original AD is included, creating ambiguity about substantive obligations outside the schedule.","Regulatory effect is conditional and administrative (listing removal) rather than a new regulatory requirement or multi-step process."],"plain_english_summary":"What this entry does (mechanical change)\n\n- The document is an entry from the Civil Aviation Safety Authority's Schedule of Airworthiness Directives (under the Civil Aviation Regulations 1998, Part 39). The entry is for AD/HS 125/109 titled “MLG Sidestay Centre Pivot Attach Nut” for British Aerospace BAe 125 series aeroplanes. The listed action in the schedule has been removed: the schedule note states, “This AD contents has been removed from the listing because the aircraft model is not currently on the register.”\n\nWho this affects\n\n- The primary immediate audience is operators and registrants of British Aerospace BAe 125 series aircraft and organisations that track active airworthiness directives. CASA (the Civil Aviation Safety Authority) is the regulator that publishes the schedule entry.\n\nWhy it matters (stated purpose and practical implications)\n\n- Stated purpose: the schedule entry was removed because the BAe 125 model is not on the Australian aircraft register (per the schedule note). The removal is an administrative change to the public listing of directives rather than a described amendment to the technical content of an airworthiness requirement.\n\n- Practical effects and incentives:\n  - For current Australian registrants: if no BAe 125 aircraft are registered in Australia, there are no active Australian-registered aircraft on which CASA would enforce this specific AD (AD/HS 125/109) via the schedule listing. That reduces any immediate compliance actions or monitoring obligations by CASA with respect to Australian-registered BAe 125s because none are registered (Schedule note: AD/HS 125/109).\n  - For operators elsewhere or for aircraft that might later be registered: the underlying AD identifier and its technical content (if it still exists in other records) may still be relevant; this schedule entry only records that it has been removed from the Australian listing because of register status (Schedule note: AD/HS 125/109).\n  - For maintainers, providers and parts suppliers: removal from the Australian schedule reduces the likelihood of Australian enforcement or mandatory compliance costs tied to this listed AD while the model remains unregistered in Australia. If the model returns to the register, the administrative status could change and compliance obligations could be reinstated.\n\nCompliance burden, decision-making, and discretion\n\n- Who pays: if the AD had been active against registered aircraft, the aircraft operator would pay compliance costs (inspections, repairs, parts, labour). With the AD removed from the Australian schedule because no such aircraft are registered, there are no current Australian-registry compliance costs triggered by this entry (Schedule note: AD/HS 125/109).\n\n- Who decides: CASA publishes and amends the Schedule of Airworthiness Directives under the Civil Aviation Regulations 1998, Part 39. The schedule note attributes the removal to the register status of the aircraft model.\n\n- Compliance burden and discretion: the entry is an administrative record: the practical regulatory effect in Australia depends on the existence of registered aircraft of that model. The schedule does not itself explain whether the technical directive has been rescinded globally, retained elsewhere, or whether CASA retains discretion to re-list the AD if registration circumstances change.\n\nTrade-offs, risks and implementation notes\n\n- Opportunity cost: removing an AD entry from the Australian schedule reduces administrative monitoring and immediate compliance obligations for Australian-registered aircraft of that type (none currently registered). If a BAe 125 is later registered in Australia, operators and CASA would need to determine whether the AD should be re‑entered or otherwise enforced.\n\n- Information risk: the schedule note is brief and does not include the AD's technical content, timeframe, or whether related records retain the directive. That creates a risk that stakeholders relying on the public schedule may miss technical obligations recorded elsewhere.\n\nSource citation: Civil Aviation Regulations 1998, Part 39; Schedule of Airworthiness Directives entry AD/HS 125/109 (MLG Sidestay Centre Pivot Attach Nut) with the schedule note stating removal because the model is not on the register."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-109-mlg-sidestay-centre-pivot-attach-nut","history":"/api/acts/ad-hs-125-109-mlg-sidestay-centre-pivot-attach-nut/history","analysis":"/api/acts/ad-hs-125-109-mlg-sidestay-centre-pivot-attach-nut/analysis","conflicts":"/api/acts/ad-hs-125-109-mlg-sidestay-centre-pivot-attach-nut/conflicts","importantCases":"/api/acts/ad-hs-125-109-mlg-sidestay-centre-pivot-attach-nut/important-cases","documents":"/api/acts/ad-hs-125-109-mlg-sidestay-centre-pivot-attach-nut/documents"}}