{"id":"F2006B04704","name":"AD/BELL 47/81 Amdt 2 - Tail Rotor Pitch Links","slug":"ad-bell-47-81-amdt-2-tail-rotor-pitch-links","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44468,"registerId":"commonwealth-F2006B04704-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 47/81 Amdt 2 - Tail Rotor Pitch Links","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)  Bell Helicopter Textron 47 (All Variants) Series Helicopters\n\n \n\nAD/BELL 47/81\n\nAmdt 2\n\n\nTail Rotor Pitch Links 10/86\n\n \n\nApplicability: All models fitted with P/N 47-641-170 series (206 type) tail rotor assembly. Document:               Bell Alert Service Bulletin 47-80-5, Revision A. Kawasaki-Bell S.B. KSB-Bell 351. Compliance:               Within 100 hours time in service after 31 July 1980.\n\nBackground: Excessive rod end bearing wear could allow displacement of the pitch link and restrict blade flapping. This Directive is revised to reflect a change in the compliance document, which introduces a replacement bolt and safety washer. This Directive has been amended to include Kawasaki-Bell Helicopters.\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":true,"description":"The original directive (issued 10/86, hence 'Amendment 2') has expanded in scope twice: first to update the compliance document to include a replacement bolt and safety washer (technical scope change), and second to explicitly include Kawasaki-Bell manufactured helicopters (geographic/manufacturer scope expansion). Originally likely applied only to US-manufactured Bell helicopters, it now covers all licensed variants."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 1 defined term implicitly referenced (P/N = Part Number)","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional logic: single applicability criterion (specific part number) with single compliance deadline","No nested exceptions or conditional sub-clauses","Straightforward command structure: identify affected aircraft → reference technical document → set compliance deadline"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Bell 47 series helicopters**.\n\n**What it does:**\n- Requires owners and operators of these helicopters to inspect or replace specific parts in the **tail rotor pitch links** (the components that control the angle of the tail rotor blades)\n- The concern is that **worn rod end bearings** could let the pitch link move out of position, which would restrict how the tail rotor blades can flap — potentially causing loss of control\n\n**Who it affects:**\n- Anyone operating Bell 47 helicopters fitted with a specific tail rotor assembly (part number 47-641-170 series, also known as the \"206 type\")\n- This includes helicopters manufactured by **Kawasaki-Bell** (a Japanese licensee), not just original Bell helicopters\n\n**What must be done:**\n- Follow the instructions in **Bell Alert Service Bulletin 47-80-5 Revision A** (or the Kawasaki-Bell equivalent)\n- This involves installing a **replacement bolt and safety washer** (an improved design)\n- Must be completed within **100 hours of flight time** after 31 July 1980\n\n**Why it matters:**\nThe tail rotor keeps the helicopter from spinning uncontrollably. If the pitch links fail due to bearing wear, the pilot could lose directional control — a serious safety risk. This directive ensures all affected helicopters get the safety upgrade."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The amendment broadened the directive by adding Kawasaki‑Bell helicopters to the applicability and updated the compliance document to require a replacement bolt and safety washer; the compliance timeframe remained a single short-term deadline."},"complexity_factors":["Narrow technical scope: applies only to helicopters fitted with P/N 47-641-170 series tail rotor assemblies (clear applicability)","Single compliance deadline: within 100 hours after a fixed date (straightforward timing)","Relies on external documents: compliance effected by following specified Bell/Kawasaki service bulletin (procedural dependency)","Modification requirement: introduces a specific replacement bolt and safety washer (parts procurement and fitment)","Amendment adds an additional manufacturer (Kawasaki‑Bell), slightly expanding affected operator pool"],"plain_english_summary":"This airworthiness directive requires operators of Bell 47 helicopters fitted with P/N 47-641-170 series tail rotor assemblies to carry out the actions in the referenced Bell/Kawasaki service bulletin within 100 flight hours after 31 July 1980. It updates the compliance instruction to introduce a replacement bolt and safety washer and adds Kawasaki‑Bell helicopters to the affected group. Operators pay for inspections, parts and any replacements required to prevent restricted blade flapping."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-47-81-amdt-2-tail-rotor-pitch-links","history":"/api/acts/ad-bell-47-81-amdt-2-tail-rotor-pitch-links/history","analysis":"/api/acts/ad-bell-47-81-amdt-2-tail-rotor-pitch-links/analysis","conflicts":"/api/acts/ad-bell-47-81-amdt-2-tail-rotor-pitch-links/conflicts","importantCases":"/api/acts/ad-bell-47-81-amdt-2-tail-rotor-pitch-links/important-cases","documents":"/api/acts/ad-bell-47-81-amdt-2-tail-rotor-pitch-links/documents"}}