{"id":"F2006B10368","name":"AD/HILLER 12/43 - Control System Linkage","slug":"ad-hiller-12-43-control-system-linkage","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115995,"registerId":"commonwealth-F2006B10368-current","compilationNumber":null,"startDate":"2026-04-03","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/HILLER 12/43 Control System Linkage 3","sectionType":"part","heading":"AD/HILLER 12/43 Control System Linkage 3/2001","content":"# AD/HILLER 12/43 Control System Linkage 3/2001\n\nApplicability: Model UH-12, UH-12A, UH-12B, UH-12C, UH-12D, UH-12E, UH-12E-L, UH-12L,\n\nand UH-12L4 helicopters.\n\nRequirement: Replace all undrilled-shank bolts at pivoting joints in the control system linkage with drilled-shank bolts, and install castellated nuts and cotter pins in accordance with Hiller Aircraft Corporation Service Bulletin No. 10-4, Revision 2, dated December 20, 1999.\n\nNote: FAA AD 2000-24-21 Amendment 39-12028 refers.\n\nCompliance: At the next annual inspection or within 12 months after 22 March 2001, whichever occurs first, unless already accomplished.\n\nThis Airworthiness Directive becomes effective on 22 March 2001.\n\nBackground: The FAA received a report of an accident caused by separation of the control system linkage of a Model UH-12E helicopter. The actions specified by this Directive are intended to prevent separation of the control system attachments at pivoting joints, and subsequent loss of control of the helicopter.\n\n![](image.003.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 24 January 2001\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 21 February 2001.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD implements a single corrective action specified for the listed UH‑12 variants — replacing undrilled bolts and fitting castellated nuts/cotter pins per the Hiller service bulletin. It restates the safety measure referenced by FAA AD 2000‑24‑21 and does not expand or narrow the listed applicability or the specified remedial action in the text provided."},"complexity_factors":["Safety‑critical mechanical modification at pivoting control‑linkage joints (Requirement) — work requires access to and replacement of fasteners on flight‑control hardware.","Normative reliance on an external manufacturer document: Hiller Service Bulletin No. 10‑4, Revision 2 (Requirement).","Specific applicability to multiple UH‑12 model variants (Applicability) — must be checked against operator fleet.","Fixed compliance window tied to next annual inspection or within 12 months after 22 March 2001 (Compliance) — scheduling and operational downtime considerations.","Reference to FAA AD 2000‑24‑21 (Note/Background) — cross‑jurisdictional alignment may affect accepted means of compliance.","Issued under CAR 1998 subregulation 39.1(1) by a CASA delegate (Intro/Background) — delegate discretion limited by the AD text."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of the listed Hiller UH‑12 helicopter models to replace undrilled‑shank bolts at pivoting control‑linkage joints with drilled‑shank bolts, fit castellated nuts and cotter pins, following Hiller Service Bulletin No. 10‑4 Rev 2. The work must be done at the next annual inspection or within 12 months after 22 March 2001. CASA says the mandate prevents control‑linkage separation and potential loss of control; operators must arrange and bear the cost and scheduling of the mechanical work."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical failure mode in specific Hiller helicopter models. The directive has not expanded beyond its initial safety purpose of preventing control system linkage separation."},"complexity_factors":["Single, specific mechanical action required (bolt replacement)","Only 9 helicopter models listed in applicability section","One compliance timeframe with a straightforward alternative trigger (next annual inspection OR 12 months)","Single cross-reference to FAA AD 2000-24-21 and Hiller Service Bulletin No. 10-4","No nested conditions, exceptions, or defined terms section","Total length: approximately 250 words"],"plain_english_summary":"This CASA Airworthiness Directive mandates owners/operators of specified Hiller UH-12 series helicopters replace certain flight-control bolts with drilled-shank bolts secured by castellated nuts and cotter pins. \n\nRequired by the next annual inspection or within 12 months of 22 March 2001, the measure prevents recurrence of a crash caused by a separated control linkage; non-compliance grounds the aircraft."},"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-hiller-12-43-control-system-linkage","history":"/api/acts/ad-hiller-12-43-control-system-linkage/history","analysis":"/api/acts/ad-hiller-12-43-control-system-linkage/analysis","conflicts":"/api/acts/ad-hiller-12-43-control-system-linkage/conflicts","importantCases":"/api/acts/ad-hiller-12-43-control-system-linkage/important-cases","documents":"/api/acts/ad-hiller-12-43-control-system-linkage/documents"}}