{"id":"F2006B03507","name":"AD/BAe 146/57 - MLG Direction Link Sub-Assembly","slug":"ad-bae-146-57-mlg-direction-link-sub-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43063,"registerId":"commonwealth-F2006B03507-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/57 - MLG Direction Link Sub-Assembly","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 146 Series Aeroplanes\n\n \n\nAD/BAe 146/57 MLG Direction Link Sub-Assembly 13/95\n\nApplicability: All Series BAe 146 aircraft.\n\n \n\nRequirement: Action in accordance with Avro International Aerospace Mandatory Service Bulletin 32-143.\n\n \n\nCompliance: Unless already accomplished, as specified in the Requirement Document with an effective date of 7 December 1995.\n\n \n\nBackground:   The manufacturer received an operator report of very heavy corrosion on the threads of the direction link tube and eye ends, which led to failure of the direction link sub- assembly.\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 directive applies to all BAe 146 series aeroplanes and requires compliance with the manufacturer’s Mandatory Service Bulletin (32-143) by the stated effective date (7 December 1995). The text does not indicate any narrowing or expansion of scope beyond addressing the reported corrosion/failure; it consistently directs operators to follow the referenced service bulletin to remedy the identified condition (see: \"Applicability: All Series BAe 146 aircraft,\" \"Requirement: Action in accordance with Avro International Aerospace Mandatory Service Bulletin 32-143,\" and \"Compliance... effective date of 7 December 1995\")."},"complexity_factors":["Cross-reference to an external technical document (Avro International Aerospace Mandatory Service Bulletin 32-143) for the substantive actions required.","Applicability covers an entire aircraft family (\"All Series BAe 146 aircraft\"), which affects many operators but keeps scope broad and simple.","Compliance is set by an effective date referenced rather than stepwise deadlines within the directive text.","The AD text omits technical detail (inspection/repair procedures, parts, labour), shifting complexity to the service bulletin.","Limited procedural detail in the AD about alternatives, approvals, or enforcement, requiring consultation of other regulatory material for full compliance context."],"plain_english_summary":"What this instrument does, mechanically:\n\n- It is an airworthiness directive titled \"AD/BAe 146/57 MLG Direction Link Sub-Assembly 13/95.\" It requires operators of the affected aeroplanes to carry out the actions specified in a manufacturer's mandatory service bulletin. (See: \"Requirement: Action in accordance with Avro International Aerospace Mandatory Service Bulletin 32-143.\")\n- The directive sets a compliance deadline by reference: unless already done, the tasks must be completed as specified in the Requirement Document with an effective date of 7 December 1995. (See: \"Compliance: ... effective date of 7 December 1995.\")\n\nWho is affected:\n\n- All operators/owners of BAe 146 series aeroplanes are within the directive's scope. (See: \"Applicability: All Series BAe 146 aircraft.\")\n\nWhy it was issued (source statement) and what that implies mechanically:\n\n- The background given is that the manufacturer received an operator report of very heavy corrosion on the threads of the direction link tube and eye ends, which led to failure of the direction link sub-assembly. The directive therefore mandates the corrective actions identified by the manufacturer. (See: \"Background: The manufacturer received an operator report of very heavy corrosion ... which led to failure of the direction link sub-assembly.\")\n\nWho pays and who decides:\n\n- The directive places the obligation to perform the required actions on aircraft operators/owners because it requires compliance with the manufacturer's Mandatory Service Bulletin. (See: \"Requirement: Action in accordance with Avro International Aerospace Mandatory Service Bulletin 32-143.\")\n- The document itself (the Civil Aviation Safety Authority’s Schedule of Airworthiness Directives) is the instrument imposing the requirement; the technical content and specified corrective steps are contained in the referenced service bulletin. (See: \"Requirement... Service Bulletin 32-143\" and \"Compliance... effective date of 7 December 1995.\")\n\nCompliance burden, discretion, and implementation points:\n\n- Compliance burden: The AD requires operators to follow the external Service Bulletin; the AD does not list the specific tasks in its text, so the practical workload (inspection, repair, replacement, downtime, parts, labour) is defined by that bulletin rather than by the AD text itself. (See: \"Requirement: Action in accordance with ... Service Bulletin 32-143.\")\n- Implementation risk and administrative linkage: The AD makes the service bulletin mandatory, so enforcement and proof of compliance will depend on records showing the bulletin's instructions were followed by the stated effective date. (See: \"Compliance... effective date of 7 December 1995.\")\n- Decision-making discretion: The AD directs operators to a mandatory manufacturer document for technical specifics; the AD text does not itself provide alternative compliance measures or exemptions. The AD does not set out any appeal, alternative means of compliance, or secondary approval process within its text. (Implicit from: the AD's singling out of the referenced Service Bulletin as the required action.)\n\nTrade-offs and opportunity costs (source-grounded):\n\n- The stated safety rationale is corrosion causing component failure; addressing it requires operator resources (labour, parts, aircraft downtime) to follow the manufacturer's remedy. (See: \"Background... very heavy corrosion ... which led to failure...\")\n- The AD centralises the technical remedy by reference to the manufacturer's Mandatory Service Bulletin, concentrating decision-making about the specific corrective actions with the manufacturer’s document rather than in the AD text itself. (See: \"Requirement: Action in accordance with ... Service Bulletin 32-143.\")\n\nLimitations of the document (what it does not say):\n\n- The AD does not set out the detailed inspection/repair steps, costs, or alternatives — those are in the referenced Service Bulletin. (See: \"Requirement... Service Bulletin 32-143.\")\n- The AD does not describe enforcement measures, penalties, or any permitted deviations in this text.\n"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect identified through manufacturer reporting. It has not expanded beyond its original purpose of mandating inspection/repair of corroded landing gear components."},"complexity_factors":["Single, specific mechanical component addressed (MLG direction link sub-assembly)","No defined terms section — uses standard aviation terminology","Single cross-reference to external technical document (Service Bulletin 32-143)","No conditional logic or nested exceptions — straightforward applicability ('All Series') and compliance deadline","Extremely short document (approximately 150 words of substantive content)","Clear, unambiguous compliance date with simple 'unless already accomplished' exception"],"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 owners and operators of all British Aerospace BAe 146 series aircraft to inspect and fix a specific mechanical problem with the **main landing gear (MLG) direction link sub-assembly** — a component that helps steer or stabilise the aircraft's wheels during landing and ground operations.\n\n**The safety issue:**\nThe manufacturer discovered severe corrosion on threaded parts of this component, which had actually caused one to break completely. Corrosion on critical flight hardware is extremely dangerous because it can lead to sudden failure without warning.\n\n**What must happen:**\nOperators must follow the repair instructions in **Avro International Aerospace Mandatory Service Bulletin 32-143** — a technical notice from the aircraft maker that details exactly what inspections or replacements are needed.\n\n**Deadline:**\nThe work must be completed by **7 December 1995** unless it was already done.\n\n**Who it affects:**\nAnyone who owns, operates, or maintains BAe 146 aircraft in Australia — including airlines, freight operators, and maintenance crews.\n\n**Why it matters:**\nThis directive prevents potential landing gear collapse or loss of directional control on the ground, which could cause runway accidents, injuries, or fatalities. Airworthiness directives are legally binding — ignoring them means the aircraft cannot legally fly."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-57-mlg-direction-link-sub-assembly","history":"/api/acts/ad-bae-146-57-mlg-direction-link-sub-assembly/history","analysis":"/api/acts/ad-bae-146-57-mlg-direction-link-sub-assembly/analysis","conflicts":"/api/acts/ad-bae-146-57-mlg-direction-link-sub-assembly/conflicts","importantCases":"/api/acts/ad-bae-146-57-mlg-direction-link-sub-assembly/important-cases","documents":"/api/acts/ad-bae-146-57-mlg-direction-link-sub-assembly/documents"}}