{"id":"F2006B07531","name":"AD/UH-1/2 - Tail Rotor Slider","slug":"ad-uh-1-2-tail-rotor-slider","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50081,"registerId":"commonwealth-F2006B07531-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/UH-1/2 - Tail Rotor Slider","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 UH-1 Series Helicopters\n\n \n\nAD/UH-1/2 Tail Rotor Slider  4/97 DM\n\n \n\nApplicability: All models.\n\n \n\nRequirement: Measure the outside diameter of the splined shaft (barrel) of the slider Part Number 204-010-720-3, or Part Number 204-010-720-003 at two points that are 90 apart on the outside circumference, at ½” to 1” from either end of the slider. Replace any slider which measures less than 1.300”.\n\n \n\nNote: FAA AD 97-01-06 refers.\n\n \n\nCompliance: Within 5 hours time in service after 12 February 1997.\n\n \n\nBackground: US Army “Breakout” spares of this item have been discovered with less than the minimum wall thickness. This Directive is to prevent a possible fatigue failure of a defective slider which would result in the loss of the tail rotor.\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":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of preventing tail rotor slider failures."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only one defined term implicitly referenced (\"time in service\")","Single, straightforward mechanical measurement requirement","No cross-references to other legislation or regulations beyond a non-binding note about the FAA directive","No conditional logic or exceptions — simple pass/fail test (measure and replace if under threshold)","Clear applicability statement with no exclusions"],"plain_english_summary":"This AD requires operators of Bell UH-1 helicopters in Australia to inspect the tail-rotor slider spline thickness and immediately replace any slider with a shaft under 1.300 inches. It responds to discovery of undersize \"breakout spare\" parts that can fatigue, crack and cause complete loss of the tail rotor — a catastrophic crash risk.\n\nCompliance was mandatory within 5 flight hours after 12 February 1997 and mirrors FAA AD 97-01-06."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope matches its stated purpose: it targets specific slider part numbers across all UH-1 models and mandates immediate inspection and replacement if below the specified diameter to address discovered defective 'breakout' spares. There is no apparent expansion or narrowing of affected items beyond the parts and models named."},"complexity_factors":["Precise physical measurement requirement (outside diameter at two points 90° apart, ½”–1” from ends) increases technical specificity but is mechanically simple.","Single numeric replacement threshold (1.300”) simplifies decision-making.","Applicability to all UH-1 models broadens operational reach despite targeting specific part numbers.","Very short compliance window (within 5 hours TIS) creates logistical pressure for operators and maintenance organisations.","No prescribed measurement tools, calibration standards, or recordkeeping procedures specified — leaves discretion to maintenance personnel.","No explicit alternative compliance or relief procedure stated.","Safety-critical consequence (possible loss of tail rotor) raises stakes and enforcement priority."],"plain_english_summary":"Requires operators of Bell UH-1 helicopters to measure the outside diameter of the specified tail‑rotor slider (P/N 204-010-720-3 or 204-010-720-003) at two points 90° apart, ½”–1” from either end, and to replace any slider smaller than 1.300”. Inspections must be completed within 5 hours time in service after 12 February 1997 and apply to all UH-1 models. Operators pay for inspections and replacements; maintenance staff must perform the measurements and remove defective parts to prevent possible fatigue failure that could cause loss of the tail rotor."}},"importantCases":[],"_links":{"self":"/api/acts/ad-uh-1-2-tail-rotor-slider","history":"/api/acts/ad-uh-1-2-tail-rotor-slider/history","analysis":"/api/acts/ad-uh-1-2-tail-rotor-slider/analysis","conflicts":"/api/acts/ad-uh-1-2-tail-rotor-slider/conflicts","importantCases":"/api/acts/ad-uh-1-2-tail-rotor-slider/important-cases","documents":"/api/acts/ad-uh-1-2-tail-rotor-slider/documents"}}