{"id":"F2006B06746","name":"AD/S-76/70 - Main Rotor Spindle Attachment Bolt","slug":"ad-s-76-70-main-rotor-spindle-attachment-bolt","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114573,"registerId":"commonwealth-F2006B06746-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.001.png)\n\n![](image.001.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.\n\nSikorsky S-76 Series Helicopters","sortOrder":0},{"sectionNumber":"AD/S-76/70 Main Rotor Spindle Attachment","sectionType":"part","heading":"AD/S-76/70 Main Rotor Spindle Attachment Bolt 13/2002","content":"# AD/S-76/70 Main Rotor Spindle Attachment Bolt 13/2002\n\nApplicability: Model S-76A, S-76B, and S-76C helicopters; except those having a serial number of 760501, or 760506 through 760515.\n\nRequirement: Inspect in accordance with Sikorsky Alert Service Bulletin 76-65-52, dated 24 July 2001.\n\nNote: FAA AD 2002-21-07 Amdt 39-12913 refers.\n\nCompliance: Within 1,250 hours time in service or 2 years after 26 November 2002, whichever occurs first; unless already accomplished.\n\nThis Airworthiness Directive becomes effective on 26 December 2002.\n\nBackground: The actions requir ed by this Directive are prompted by the discovery of improper bolts installed on a helicopter during its production. Having incorrect bolts installed could result in reduced hub or bolt fatigue life, separation of the main rotor blade at the spindle attachment, and subsequent loss of control of the helicopter.\n\n![Signature of David Alan Villiers Delegate of the Civil Aviation Safety Authority](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 15 November 2002\n\n![](image.001.png)","sortOrder":1}],"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":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific manufacturing defect in a specific helicopter model. The scope remains precisely limited to the identified unsafe condition (improper bolts in main rotor assembly) and has not expanded beyond this original purpose."},"complexity_factors":["Single, specific mechanical component addressed (main rotor spindle attachment bolt)","Only 3 defined applicability criteria (model types plus serial number exceptions)","Simple compliance structure: one inspection method, one deadline formula","No nested exceptions or conditional logic beyond the serial number carve-out","Cross-reference to only one external document (FAA AD) and one manufacturer bulletin","Total length: approximately 200 words of substantive text"],"plain_english_summary":"This CASA safety order requires owners/operators of Sikorsky S‑76A/B/C helicopters (except certain serial numbers) to inspect the main rotor spindle attachment bolt per Sikorsky Alert Service Bulletin 76‑65‑52. It responds to reports that incorrect bolts were fitted at manufacture, risking accelerated wear and possible rotor blade separation. The inspection must be completed by 26 November 2004 or within 1,250 flight hours/2 years, whichever comes first."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD enforces an inspection and any corrective action per the manufacturer's service bulletin for identified S‑76 models, with specific serial-number exclusions. It does not expand coverage beyond those models or add broader regulatory obligations; it operationalises a targeted safety response to discovered incorrect bolts."},"complexity_factors":["Single, focused mandatory action (inspection) limits legal complexity","Reliance on an external technical document (Sikorsky Alert Service Bulletin 76‑65‑52) for procedures and corrective actions","Serial-number exceptions narrow applicability but require record-checking","Fixed dual compliance metric (hours-in-service or calendar time) creates operational scheduling considerations","Reference to FAA AD 2002-21-07 introduces cross-jurisdictional linkage","Potential follow-on corrective work (repairs/replacements) depends on inspection outcomes, adding variable cost and downtime"],"plain_english_summary":"This Airworthiness Directive requires operators of Sikorsky S‑76A, S‑76B and S‑76C helicopters (with listed serial-number exceptions) to inspect the main rotor spindle attachment bolt in accordance with Sikorsky Alert Service Bulletin 76‑65‑52. Compliance must occur within 1,250 flight hours or two years from 26 November 2002. CASA (by delegate) issues the mandate; operators bear inspection, repair and downtime costs. The AD follows discovery of incorrect production bolts that could reduce fatigue life and risk main rotor separation."}},"importantCases":[],"_links":{"self":"/api/acts/ad-s-76-70-main-rotor-spindle-attachment-bolt","history":"/api/acts/ad-s-76-70-main-rotor-spindle-attachment-bolt/history","analysis":"/api/acts/ad-s-76-70-main-rotor-spindle-attachment-bolt/analysis","conflicts":"/api/acts/ad-s-76-70-main-rotor-spindle-attachment-bolt/conflicts","importantCases":"/api/acts/ad-s-76-70-main-rotor-spindle-attachment-bolt/important-cases","documents":"/api/acts/ad-s-76-70-main-rotor-spindle-attachment-bolt/documents"}}