{"id":"F2006B07536","name":"AD/UH-1/8 - Tail Rotor Hub","slug":"ad-uh-1-8-tail-rotor-hub","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50096,"registerId":"commonwealth-F2006B07536-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/UH-1/8 Tail Rotor Hub 8/2000","sectionType":"part","heading":"AD/UH-1/8 Tail Rotor Hub 8/2000","content":"# AD/UH-1/8 Tail Rotor Hub 8/2000\n\nApplicability: Models UH1L, TH1L and UH1H.\n\nRequirement: Remove from service tail rotor hub P/N 204-011-801-121 with any serial number IT0001 to and including IT0010.\n\nCompliance: Before further flight after the effective date of this directive.\n\nNote: FAA AD 89-20-12 refers.\n\n![Signature of David Alan Villiers Delegate of the Civil Aviation Safety Authority](image.003.png)  \nThis Airworthiness Directive becomes effective on 10 August 2000\\. Background: This directive is issued to prevent failure of certain tail rotor hubs.\n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 6 July 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 12 July 2000.","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific unsafe condition in specific serial-numbered tail rotor hubs. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 300 words)","Only 3 defined models in applicability section","Single, unambiguous requirement with no exceptions or conditions","No cross-references to other legislation (only a reference to related FAA directive for information)","Clear compliance deadline ('before further flight')","No nested definitions or interpretive provisions"],"plain_english_summary":"CASA requires immediate removal from service — before the next flight — of Bell tail-rotor hubs P/N 204-011-801-121, S/N IT0001–IT0010, from UH-1L, TH-1L and UH-1H helicopters. \n\nThis grounding order, mandatory from 10 August 2000, prevents catastrophic tail-rotor hub failure that can cause loss of control and fatal crashes."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive’s scope is limited to specific tail rotor hubs on listed helicopter models and requires their removal to prevent failure (Requirement; Applicability; Background). The text contains no indication that the scope has been expanded or narrowed from the stated purpose; affected parties are owners/operators of the listed aircraft who must remove the specified parts before further flight (Compliance)."},"complexity_factors":["Narrow applicability: only UH1L, TH1L and UH1H models (Applicability).","Single clear mandatory action: remove specified part numbers/serials (Requirement).","Immediate compliance required: before further flight (Compliance).","Precise identification by part number and serial range reduces ambiguity but requires operators to track serials.","Cross-reference to FAA AD may require consulting external material (Note: FAA AD 89-20-12).","Regulatory provenance: issued by CASA delegate under CAR 1998 s39.1(1), showing administrative authority but no technical repair procedure included."],"plain_english_summary":"This Airworthiness Directive requires removal from service of tail rotor hub P/N 204-011-801-121, serial numbers IT0001–IT0010, on UH1L, TH1L and UH1H helicopters (Applicability; Requirement). Operators must remove the identified hubs before the next flight (Compliance). CASA issued the directive under CAR 1998 subregulation 39.1(1) to prevent failure of those hubs (Background). The immediate cost, downtime and replacement sourcing fall on the affected aircraft owners/operators."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-uh-1-8-tail-rotor-hub","history":"/api/acts/ad-uh-1-8-tail-rotor-hub/history","analysis":"/api/acts/ad-uh-1-8-tail-rotor-hub/analysis","conflicts":"/api/acts/ad-uh-1-8-tail-rotor-hub/conflicts","importantCases":"/api/acts/ad-uh-1-8-tail-rotor-hub/important-cases","documents":"/api/acts/ad-uh-1-8-tail-rotor-hub/documents"}}