{"id":"F2006B04399","name":"AD/BELL 205/62 - 42 Degree Tail Rotor Drive Gearbox","slug":"ad-bell-205-62-42-degree-tail-rotor-drive-gearbox","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44224,"registerId":"commonwealth-F2006B04399-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 205/62 - 42 Degree Tail Rotor Drive Gearbox","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\nBell Helicopter Textron 205 Series Helicopters\n\n \n\nAD/BELL 205/62 42 Degree Tail Rotor Drive Gearbox 9/95\n\nApplicability: All Bell 205 and civil registered UH-1 series helicopters fitted with P/N 204-040-003- 023 or 204-040-003-037 42 degree tail rotor drive gearbox.\n\n \n\nRequirement: Action in accordance with the technical requirements of FAA AD 95-10-07 Amdt 39- 9224 or FAA AD 95-10-08 Amdt 39-9225 as applicable.\n\n \n\nNote 1: FAA AD 95-10-08 Amdt 39-9225 refers to UH-1 series helicopters.\n\n \n\nNote 2: A torque event is defined as a take-off or an (Internal or External) load lifting event.\n\n \n\nCompliance: As specified in the Requirement Document with revised effective date of 17 August 1995.\n\n \n\nBackground: Failure of the 42 degree tail rotor drive gearbox has caused a number of helicopter accidents.\n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument’s scope is limited to Bell 205 and civil UH-1 series helicopters fitted with the two specified 42-degree tail rotor drive gearbox part numbers and requires operators to follow the technical steps set out in the referenced FAA ADs (Applicability; Requirement). The stated purpose (addressing gearbox failures that caused accidents) aligns with the applied scope (Background). There is no indication in the text that the instrument expands or contracts coverage beyond that stated applicability and the FAA-specified remedies (Applicability; Requirement; Background)."},"complexity_factors":["Dependence on external documents (FAA AD 95-10-07 and FAA AD 95-10-08) for the substantive technical steps (Requirement).","Specific part-numbered applicability (two P/Ns) requires operators to check equipment records (Applicability).","Compliance timing delegated to an external Requirement Document with a revised effective date, rather than listed in the AD itself (Compliance).","A defined operational trigger (\"torque event\") that may affect when actions are required, requiring event tracking (Note 2).","Different FAA ADs apply depending on helicopter model (Bell 205 vs UH-1), requiring model-specific interpretation (Requirement; Note 1)."],"plain_english_summary":"This AD requires owners/operators of Bell 205 and civil UH‑1 helicopters fitted with the two specific 42° tail‑rotor drive gearbox part numbers to carry out the technical actions set out in FAA AD 95‑10‑07 or 95‑10‑08 (as applicable). It defines “torque events” (take‑offs or load lifts) that affect when actions apply. The measure addresses gearbox‑failure safety risks and places compliance costs and maintenance burden on operators and their maintenance providers."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical failure mode. It has not expanded beyond its original purpose of mandating inspection/replacement of a faulty gearbox component."},"complexity_factors":["Single, specific mechanical component targeted (42-degree tail rotor drive gearbox)","Only two part numbers affected","Short document (approximately 150 words)","Minimal defined terms (only 'torque event' explicitly defined)","Simple conditional structure: if helicopter has specified part, comply with referenced FAA directive","No nested exceptions or complex cross-referencing within the document itself (relies on external FAA documents for technical detail)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific Bell helicopters.\n\n**What it does:**\nOrders owners and operators of certain Bell 205 and UH-1 helicopters to inspect or replace a specific part — the **42-degree tail rotor drive gearbox** (part numbers 204-040-003-023 or 204-040-003-037).\n\n**Why it matters:**\nThis gearbox has failed multiple times, causing helicopter crashes. The directive requires compliance with equivalent US Federal Aviation Administration (FAA) safety orders to prevent further accidents.\n\n**Who must comply:**\n- All Bell 205 helicopters with the specified gearbox\n- Civil-registered UH-1 helicopters (military Huey variants used in civilian operations) with the specified gearbox\n\n**Key requirement:**\nOperators must follow the technical instructions in **FAA AD 95-10-07** or **FAA AD 95-10-08** (depending on helicopter model). These US directives specify inspection schedules and replacement procedures.\n\n**Special definition:**\nA \"torque event\" — which triggers certain inspection requirements — means any take-off or external load lifting operation.\n\n**Compliance deadline:**\nAs specified in the FAA documents, with an effective date of 17 August 1995."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-205-62-42-degree-tail-rotor-drive-gearbox","history":"/api/acts/ad-bell-205-62-42-degree-tail-rotor-drive-gearbox/history","analysis":"/api/acts/ad-bell-205-62-42-degree-tail-rotor-drive-gearbox/analysis","conflicts":"/api/acts/ad-bell-205-62-42-degree-tail-rotor-drive-gearbox/conflicts","importantCases":"/api/acts/ad-bell-205-62-42-degree-tail-rotor-drive-gearbox/important-cases","documents":"/api/acts/ad-bell-205-62-42-degree-tail-rotor-drive-gearbox/documents"}}