{"id":"F2006B04531","name":"AD/BELL 206/8 Amdt 2 - Transmission Spider - Inspection and Life Limitation","slug":"ad-bell-206-8-amdt-2-transmission-spider-inspection-and-life-limitation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114246,"registerId":"commonwealth-F2006B04531-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/8 Amdt 2 - Transmission Spider - Inspection and Life Limitation","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nBell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters\n\nAD/BELL 206/8\n\nAmdt 2\n\n  \n\nTransmission Spider \\- Inspection and Life Limitation\n\n  \n3/70\n\nApplicability: All models fitted with transmission spider P/N 206-040- 041-001. Document: Bell SB No. 206A-14, Rev. B.\n\nNote: Agusta SB No. BT206-37 refers.\n\nCompliance: 1. All spiders with 450 hours or more total time in service must be retired within 50 hours time in service.\n\n    2. All spiders with less than 450 hours total time in service must be retired at or before 500 hours total time in service.\n\n    3. All transmissions fitted with spiders that have 300 hours or more total time in service must have the magnetic plug checked for metal particles at each daily or overnight inspection.\n\nBackground: AD/Agusta 206/7A equivalent.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 2 of an existing Airworthiness Directive, indicating it has been updated twice. However, the scope remains tightly focused on the original safety issue — the transmission spider's life limitation and inspection requirements. The amendments likely refined hour thresholds or clarified applicability based on operational experience, but have not expanded beyond the specific part and safety concern originally identified."},"complexity_factors":["Very short document (approximately 150 words)","Only 3 compliance requirements with clear numerical thresholds","Single defined part number (P/N 206-040-041-001)","No nested exceptions or conditional logic","Simple binary applicability test (fitted with specific part number or not)","Cross-reference to only 2 related service bulletins for technical details"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to specific Bell and Agusta Bell helicopter models.\n\n**What it does:**\n- **Targets a specific part:** The \"transmission spider\" (a component in the helicopter's transmission system that helps transfer power from the engine to the rotor).\n- **Sets hard retirement deadlines:** Helicopter operators must permanently remove and replace this part once it reaches certain flight hour limits — either within 50 hours if it's already done 450+ hours, or by 500 hours total if it's newer.\n- **Requires extra monitoring:** For parts with 300+ hours, operators must check the transmission's magnetic plug (a device that catches metal debris) every day or overnight to catch early signs of failure.\n\n**Who it affects:**\n- Owners and operators of Bell 206 and Agusta Bell 206 series helicopters fitted with transmission spider part number 206-040-041-001.\n- Maintenance engineers responsible for these aircraft.\n\n**Why it matters:**\nThis directive prevents catastrophic transmission failures. The transmission spider has a known safety issue — likely fatigue or cracking — that could cause the helicopter to lose power to the rotor. The mandatory retirement limits and inspections are designed to catch or prevent failures before they cause accidents."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The document is presented as Amendment 2 to AD/BELL 206/8 (Amdt 2) which indicates it modifies a prior airworthiness directive. The supplied text does not specify the prior thresholds or the exact differences from the earlier version, only the current applicability and the retirement/inspection requirements now mandated (Amdt 2; Applicability; Compliance 1–3)."},"complexity_factors":["Narrow applicability to a single part number and helicopter series (Applicability).","Clear, numeric retirement thresholds and inspection trigger points (Compliance 1–3).","Direct mandatory actions (retire within X hours; inspect at each daily/overnight inspection) leaving little regulatory discretion (Compliance 1–3).","Reference to an external service bulletin for technical procedures (Bell SB No. 206A-14, Rev. B) adds a dependency operators must consult (Applicability).","Labelled as an amendment (Amdt 2) indicating a change from a prior AD, but the text supplied does not include prior-version differences (Amdt 2; Background)."],"plain_english_summary":"This directive applies to Bell/Agusta Bell 206-series helicopters fitted with transmission spider P/N 206-040-041-001 and requires operators to retire spiders at fixed hour limits (spiders with ≥450 hours must be retired within 50 flight hours; all spiders must be retired by 500 hours) and to check the transmission magnetic plug for metal particles at each daily/overnight inspection once a spider reaches 300 hours. It’s mandatory, enforced by the regulator, and shifts replacement, inspection and downtime costs to aircraft owners/operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-8-amdt-2-transmission-spider-inspection-and-life-limitation","history":"/api/acts/ad-bell-206-8-amdt-2-transmission-spider-inspection-and-life-limitation/history","analysis":"/api/acts/ad-bell-206-8-amdt-2-transmission-spider-inspection-and-life-limitation/analysis","conflicts":"/api/acts/ad-bell-206-8-amdt-2-transmission-spider-inspection-and-life-limitation/conflicts","importantCases":"/api/acts/ad-bell-206-8-amdt-2-transmission-spider-inspection-and-life-limitation/important-cases","documents":"/api/acts/ad-bell-206-8-amdt-2-transmission-spider-inspection-and-life-limitation/documents"}}