{"id":"F2006B07523","name":"AD/UH-1/1 - Tail Rotor Blades","slug":"ad-uh-1-1-tail-rotor-blades","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50058,"registerId":"commonwealth-F2006B07523-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/UH-1/1 - Tail Rotor Blades","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBell UH-1 Series Helicopters\n\nAD/UH-1/1 Tail Rotor Blades 9/96 DM\n\nApplicability: All models fitted with tail rotor blades P/N 204-011-702-015 or -121 with serial numbers A-20262 to A-20268, A-20270 to A-20282, A-20284 to A-20287, A-20289 to A-20422, A-20424 to A-20428, A-20430 to A-20433, A-20435 to A-20464, A- 20466 to A-20497, A-20499 to A21019, A-21027 to A-21031, A-21041, A-21047, A-\n\n21049, and A-21059\n\nRequirement: 1. Clean the tail rotor (TR) blades using a mild detergent and water to remove soot and grime; and then visually inspect each TR blade for peeling, flaking, or bubbling paint, or visible corrosion along the bond lines, viewed from the root and tip ends of each blade, and at the abrasion strip bond line on both faces of the blade from the root to the tip.\n\n    2. If peeling, flaking, or bubbling paint is found remove the paint from the area and inspect for corrosion. If no corrosion is found refinish blade and return to service.\n\n    3. Remove from service any blade where corrosion is found. Replacement with blades not listed in the Applicability terminates this Directive.\n\nNote 1: FAA AD 96-12-26 refers.\n\nNote 2: BHTI ASB 204-96-48 Rev A refers.\n\nCompliance: Within 10 hours time in service after 26 June 1996, thereafter at intervals not exceeding seven days.\n\nBackground: The manufacturer has reported that certain serial number tail rotor blades were manufactured with internal leading edge doublers fabricated from clad aluminium material instead of bare aluminium material. The bond strength of clad aluminium material declines rapidly with exposure to normal environmental conditions.\n\nThe condition, if not corrected could lead to debonding of the main spar leading edge doubler which in turn could cause failure of the TR blade and subsequent loss of control of the helicopter.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific manufacturing defect in specific tail rotor blades. It has not expanded beyond its original purpose of ensuring the airworthiness of affected Bell UH-1 tail rotor blades."},"complexity_factors":["Single, discrete safety issue addressed (specific material defect in specific serial numbers)","Straightforward three-step compliance requirement (clean, inspect, remove if corroded)","Only 2 cross-references (to FAA directive and manufacturer service bulletin)","Clear applicability section with explicit serial number ranges (though these are numerous, they are simply listed)","Simple compliance timeline (10 hours initially, then 7-day intervals)","No nested exceptions or conditional logic — only one decision point (corrosion found = remove from service)","No defined terms section; all technical terms explained in context or self-explanatory"],"plain_english_summary":"This Airworthiness Directive requires operators of Bell UH‑1 helicopters fitted with specified tail‑rotor blade serial numbers to inspect those blades for corrosion caused by improperly clad aluminium that can lead to in‑flight failure. Affected operators must clean and visually inspect bond lines, remove any corroded blades from service, and may replace them with unaffected blades to lift the requirement. Initial inspection is mandated within 10 flight hours after 26 June 1996 and then weekly."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope is limited to the specified P/N and serial numbers and requires inspection and removal for corrosion; the directive also states that replacing an affected blade with a blade not listed in the Applicability terminates the directive. The instrument as presented does not indicate any change to that original scope."},"complexity_factors":["Applicability narrowly tied to part number P/N 204-011-702-015 or -121 and an extensive list of serial numbers — requires accurate identification of affected blades.","Very short initial compliance window (\"Within 10 hours time in service after 26 June 1996\") and recurring inspections at intervals not exceeding seven days — high-frequency compliance burden.","Prescribed procedure is simple (clean with mild detergent and water; visual inspection for peeling, flaking, bubbling paint or visible corrosion along bond lines) but must be performed from root and tip ends and at abrasion strip bond lines on both faces.","Mandatory action: remove from service any blade where corrosion is found; replacement with blades not listed in the Applicability terminates the Directive — creates a replacement/disposition decision for operators.","Cross-references to FAA AD 96-12-26 and BHTI ASB 204-96-48 Rev A mean operators may need to consult external documents for background/repair procedures.","Costs (who pays): operators/maintenance organisations incur labour, refinishing, and replacement costs; potential operational impact from grounded aircraft.","Risk context: links a specific manufacturing variance (clad aluminium leading edge doublers) to bond‑strength decline and possible structural failure — noncompliance carries direct safety consequences."],"plain_english_summary":"Requires operators of Bell UH‑1 helicopters fitted with certain tail‑rotor blades (specific part and serial numbers) to clean and visually inspect those blades for peeling paint and corrosion within 10 flight hours and then at least weekly. Any blade showing corrosion must be removed from service; fitting a blade not listed in the applicability ends the directive. Operators and maintenance providers bear the inspection, refinishing and replacement costs; the rule is intended to prevent bond‑line debonding of the blade leading edge doubler."},"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-1-1-tail-rotor-blades","history":"/api/acts/ad-uh-1-1-tail-rotor-blades/history","analysis":"/api/acts/ad-uh-1-1-tail-rotor-blades/analysis","conflicts":"/api/acts/ad-uh-1-1-tail-rotor-blades/conflicts","importantCases":"/api/acts/ad-uh-1-1-tail-rotor-blades/important-cases","documents":"/api/acts/ad-uh-1-1-tail-rotor-blades/documents"}}