{"id":"F2006B10370","name":"AD/HILLER 12/8 Amdt 3 - Main Rotor Blade Fork","slug":"ad-hiller-12-8-amdt-3-main-rotor-blade-fork","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116001,"registerId":"commonwealth-F2006B10370-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HILLER 12/8 Amdt 3 - Main Rotor Blade Fork","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)  \nHiller UH-12 Series Helicopters\n\nAD/HILLER 12/8\n\nAmdt 3\n\n  \n\nMain Rotor Blade Fork 10/86 TX\n\nApplicability: All aircraft fitted with Main Rotor Blade Fork. P/N 52110-3\n\nRequirement: 1. Inspect all installed forks P/N 52110-3 to verify that each has a manufacturer’s serial number permanently displayed on its outer surface. Remove from service forks found not to be serialized.\n\n    2. Visually inspect the P/N 52110-3 forks for cracks in the area of the outboard tension-torsion bar retention bolt hole. Washers and nuts need not be removed for this inspection.\n\nNote: This inspection may be accomplished by the pilot in command, in which case the precise AD reference shall be entered in a certification made on the maintenance release coincident with that for the daily inspection.\n\n    3. Remove the nut, washer and bolt and inspect the bolt hole bore and adjacent milled surfaces using a dye penetrant technique in accordance with ANO 108.10.\n\nCompliance: Requirement 1. Within 10 hours’ time in service after 15 September 1986.\n\nRequirement 2. At each daily or overnight inspection.\n\nRequirement 3. Within 10 hours’ time in service after 15 September 1986 or before achieving 250 hours component time in service, whichever is the later; and thereafter at intervals not exceeding 100 hours component time in service.\n\nNote: Inspections performed in accordance with the previous issues of this Directive satisfy the requirements of this issue.\n\nBackground: This Directive implements the requirements of FAA AD 86-17-02 which supersedes FAA AD 79-18-04. Amendment 3 to the Directive extends the dye penetrant inspection to forks of all serial numbers following a fatal accident in the USA which involved failure of a shot peened fork.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original AD (implied by Amendment 3) appears to have limited certain inspections to specific serial number ranges or manufacturing batches. Amendment 3 expands the scope to cover 'forks of all serial numbers' following the fatal US accident involving a shot peened fork. This represents a scope expansion from targeted inspection to universal inspection requirements."},"complexity_factors":["Short, single-purpose instrument (approximately 250 words)","Only 3 substantive requirements with clear, numbered compliance deadlines","Limited defined terms (only specific part number P/N 52110-3 and reference to ANO 108.10 — an existing aviation standard)","Simple conditional logic: 'whichever is the later' for one compliance date","No nested exceptions or cross-references to other legislation beyond the FAA AD reference in the background","Plain language structure with explicit applicability and compliance sections"],"plain_english_summary":"This CASA Airworthiness Directive targets Hiller UH‑12 main rotor blade forks (p/n 52110‑3) after cracks around a bolt hole — and a fatal U.S. accident — showed failures even on shot‑peened parts. It requires permanent serial numbers (remove unmarked forks), daily pilot visual checks for cracks, and licensed‑maintenance dye‑penetrant inspections of the bolt hole area. Amendment 3 expands the mandatory deep inspection to all forks, closing a safety gap."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 3 broadened the scope by extending the dye-penetrant inspection to forks of all serial numbers following a fatal accident (Background). Previously the directive followed earlier FAA ADs; this amendment makes the non-destructive inspection requirement apply across the entire P/N 52110-3 population rather than a limited subset. The instrument therefore increases the number of components and operators subject to mandatory dye-penetrant inspection and recurring checks (Applicability; Requirement 3; Compliance)."},"complexity_factors":["Multiple inspection types with different procedures: serial number verification, recurrent visual checks, and dye-penetrant inspection (Requirements 1–3).","Staggered compliance deadlines and recurring intervals: 10 hours after 15 Sept 1986 for some tasks; before 250 component hours and then every 100 component hours for dye-penetrant (Compliance).","Operator-versus-maintainer roles: daily visual may be performed by pilot in command with a maintenance release entry, while dye-penetrant requires removal of nut/washer/bolt and a specific non-destructive test standard (Requirement 2 note; Requirement 3).","Applicability to a parts population rather than individual serial ranges: affects all aircraft fitted with P/N 52110-3, increasing the population requiring inspection (Applicability; Background).","Normative references to external standard for dye penetrant technique (ANO 108.10) introduce dependence on another document for compliance.","Recordkeeping and removal-from-service consequence for non-compliant items add administrative and replacement cost considerations (Requirement 1; Compliance)."],"plain_english_summary":"This airworthiness directive requires owners/operators of Hiller UH-12 helicopters fitted with Main Rotor Blade Fork P/N 52110-3 to check that each fork is serialised, to perform daily visual checks for cracks around the outboard tension-torsion bar retention bolt hole, and to carry out dye-penetrant inspection of the bolt hole bore after removing the bolt hardware within set time limits. The rule shifts inspection responsibility onto operators (the pilot may do daily checks) and imposes removal-from-service and recurring inspection obligations to address a previously identified in-service failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hiller-12-8-amdt-3-main-rotor-blade-fork","history":"/api/acts/ad-hiller-12-8-amdt-3-main-rotor-blade-fork/history","analysis":"/api/acts/ad-hiller-12-8-amdt-3-main-rotor-blade-fork/analysis","conflicts":"/api/acts/ad-hiller-12-8-amdt-3-main-rotor-blade-fork/conflicts","importantCases":"/api/acts/ad-hiller-12-8-amdt-3-main-rotor-blade-fork/important-cases","documents":"/api/acts/ad-hiller-12-8-amdt-3-main-rotor-blade-fork/documents"}}