{"id":"F2006B10358","name":"AD/HILLER 12/30 Amdt 2 - Main Rotor Assembly","slug":"ad-hiller-12-30-amdt-2-main-rotor-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115971,"registerId":"commonwealth-F2006B10358-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HILLER 12/30 Amdt 2 - Main Rotor Assembly","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 12/30\n\nAmdt 2\n\n  \nMain Rotor Assembly 8/86\n\nApplicability: All models UH-12D, UH-12E, UH-12E4, OH-23F, OH-23G and all models converted by STC SH 178WE and STC SH 177 WE equipped with main rotor blades assembly Parsons P/No. 2253-1101.\n\nRequirement: Action in accordance with Rogerson Hiller SB UH12-51-6 Revision dated 19 December 1985.\n\nNote: FAA AD 80-14-12 Amdt 39-3836 refers.\n\nCompliance: As per Requirement Document.\n\nNote: The Daily Inspection may be accomplished by the pilot in command, in which case an entry and certification for this AD shall be made in Col. 2 Part 3 of the Maintenance Release on each occasion.\n\nBackground: The main rotor blade spar may develop bond separation and voids leading to spar cracking. This Amendment introduces a daily visual inspection, reduces the dye penetrant inspection period from 100 hours’ time in service to 25 hours’ time in service, adds a bond separation and void inspection by “coin tapping” and specifies an overhaul requirement.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose of ensuring main rotor blade safety on specific Hiller helicopter models. The changes introduced (daily inspections, reduced inspection intervals, coin tapping, and overhaul requirements) are incremental safety enhancements directly addressing the identified spar cracking risk, not scope expansion."},"complexity_factors":["Short, single-purpose directive (approximately 200 words)","Only 6 defined model variants in applicability section","Single cross-reference to FAA AD 80-14-12 for additional context","One conditional provision (pilot-performed daily inspection requires specific logbook entry)","Technical terminology requires aviation knowledge but is standard for the field (spar, bond separation, dye penetrant, coin tapping)","No nested exceptions or complex conditional logic","Compliance delegated entirely to referenced service bulletin (Rogerson Hiller SB UH12-51-6)"],"plain_english_summary":"This safety directive requires owners/operators of certain Hiller UH‑12 series helicopters with Parsons main rotor blade assemblies to perform regular inspections and overhauls: daily pilot visual checks (logged in Column 2, Part 3 of the Maintenance Release), coin‑tapping for internal debonding, dye‑penetrant inspections every 25 flight hours, and specified overhaul intervals.\n\nIt affects pilots, licensed maintenance engineers and owners because hidden bond separation/voids in the rotor spar can lead to cracking and catastrophic failure, so earlier detection prevents accidents."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 2 tightens the inspection and maintenance regime compared with the prior requirement by adding a daily visual inspection, reducing dye‑penetrant interval from 100 to 25 hours, adding coin‑tapping checks, and specifying an overhaul requirement (Background). Mechanically, this expands the AD's operational scope and recurring compliance costs for affected operators while permitting limited delegation of daily inspections to pilots with a maintenance release entry (Note)."},"complexity_factors":["Cross‑reference to Rogerson Hiller SB UH12‑51‑6 for procedural detail — the AD defers key steps to an external document (Requirement).","Multiple inspection methods and intervals: daily visual, dye‑penetrant at 25‑hour TIS, and coin‑tapping for bond separation (Requirement; Background).","Pilot‑performed daily inspection allowed but requires maintenance record entry in Part 3 Col.2 of the Maintenance Release (Note) — shifts some responsibility and adds administrative action.","Overhaul requirement specified but timing/details not set in the AD text, creating reliance on the service bulletin or operator judgement (Background; Requirement).","Applicability covers several models and STC conversions, so ensuring correct identification of affected aircraft can be administratively burdensome (Applicability).","Reference to FAA AD 80‑14‑12 introduces interjurisdictional linkage for justification but does not itself supply procedural steps (Note).","Shortened dye‑penetrant interval (100→25 hours) materially increases maintenance frequency and cost for operators (Background)."],"plain_english_summary":"This AD requires operators of Hiller UH‑12 series helicopters (and specified STC conversions) fitted with Parsons P/No. 2253‑1101 main rotor blade assemblies to follow Rogerson Hiller SB UH12‑51‑6: add a daily visual inspection (pilot may perform), shorten dye‑penetrant inspections from 100 to 25 hours TIS, add a coin‑tapping check for bond separation/voids, and require overhaul. It targets bond separation that can lead to spar cracking. Operators bear increased inspection, maintenance and recordkeeping costs; one daily check may be delegated to pilots with an entry in the Maintenance Release."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hiller-12-30-amdt-2-main-rotor-assembly","history":"/api/acts/ad-hiller-12-30-amdt-2-main-rotor-assembly/history","analysis":"/api/acts/ad-hiller-12-30-amdt-2-main-rotor-assembly/analysis","conflicts":"/api/acts/ad-hiller-12-30-amdt-2-main-rotor-assembly/conflicts","importantCases":"/api/acts/ad-hiller-12-30-amdt-2-main-rotor-assembly/important-cases","documents":"/api/acts/ad-hiller-12-30-amdt-2-main-rotor-assembly/documents"}}