{"id":"F2006B06699","name":"AD/S-76/16 Amdt 2 - Main Rotor Blade Root End - Inspection for Fatigue Cracking","slug":"ad-s-76-16-amdt-2-main-rotor-blade-root-end-inspection-for-fatigue-cracking","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114506,"registerId":"commonwealth-F2006B06699-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/S-76/16 Amdt 2 - Main Rotor Blade Root End - Inspection for Fatigue Cracking","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Sikorsky S-76 Series Helicopters\n\n \n\nAD/S-76/16\n\nAmdt 2\n\n\nMain Rotor Blade Root End - Inspection for Fatigue Cracking\n\n\n4/85\n\n \n\nApplicability: All models fitted with main rotor blades P/N 76150-09000 or 76150-09100. Requirement:               Sikorsky S76 Alert Customer Service Bulletin no. 76-65-18C.\n\nCompliance: As detailed in requirement document. Inspections carried out in accordance with the previous issue of this directive, meet the requirements of this issue.\n\n \n\nBackground: The directive has been amended to nominate ACSB 76-65-18C as a more appropriate requirement document than the Composite Materials Manual. FAA AD 84-10-02 also refers to this subject.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment changes the operative procedural document by nominating Sikorsky S76 Alert Customer Service Bulletin no. 76-65-18C instead of the Composite Materials Manual as the required source of inspection procedures. The applicability (affected models and part numbers) and the requirement to inspect remain in force, and inspections done under the previous issue are accepted as compliant. (Requirement; Compliance; Background)"},"complexity_factors":["Short, focused directive limited to a specific component and two part numbers (Applicability).","Dependence on an external manufacturer service bulletin (ACSB 76-65-18C) for procedural detail (Requirement; Background).","Simple transitional rule accepting prior-compliant inspections (Compliance).","No detailed inspection intervals, methods or enforcement mechanisms contained in the AD text itself (Requirement).","Reference to a related FAA AD but no cross-jurisdictional procedural integration described (Background)."],"plain_english_summary":"This AD mandates inspections of Sikorsky S‑76 main rotor blade root ends (PNs 76150‑09000/09100) for fatigue cracking; owners/operators must arrange and fund the inspections and any corrective work. Compliance is achieved by following Sikorsky Alert CSB 76‑65‑18C (the AD’s binding procedural document). Previously completed inspections under the prior AD remain acceptable."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing directive. The amendment simply updates the reference document from a Composite Materials Manual to a specific Sikorsky Customer Service Bulletin (76-65-18C). The scope — inspecting S-76 main rotor blade roots for fatigue cracking — remains identical to the original 1985 directive (noted as \"4/85\"). No expansion of affected aircraft, inspection methods, or compliance timelines."},"complexity_factors":["Extremely short document (under 200 words)","Only 2 defined part numbers for applicability","Single requirement referencing an external technical document (Sikorsky bulletin)","No nested conditions or exceptions — straightforward compliance pathway","Simple grandfathering clause for previous inspections","No cross-references to other legislation beyond noting related FAA directive"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific maintenance actions on certain helicopters.\n\n**What it does:** It orders owners and operators of **Sikorsky S-76 series helicopters** to inspect the **main rotor blade root ends** (the part where the rotor blade attaches to the helicopter hub) for **fatigue cracking** (tiny cracks that develop from repeated stress and can lead to catastrophic failure).\n\n**Who must comply:** Anyone operating S-76 helicopters fitted with specific main rotor blade part numbers: **76150-09000 or 76150-09100**.\n\n**What must be done:** Operators must follow the procedures in **Sikorsky Alert Customer Service Bulletin 76-65-18C** (a technical document from the manufacturer detailing how to perform the inspection). The bulletin replaces an earlier reference to a \"Composite Materials Manual\" as the proper guide for these checks.\n\n**Key relief:** If you've already done inspections under the previous version of this directive, those count — you don't need to start over.\n\n**Why it matters:** Fatigue cracks in rotor blades can grow undetected and cause blade failure in flight, which is almost always fatal. This directive ensures critical safety checks happen on a defined schedule to catch problems before they become disasters."}},"importantCases":[],"_links":{"self":"/api/acts/ad-s-76-16-amdt-2-main-rotor-blade-root-end-inspection-for-fatigue-cracking","history":"/api/acts/ad-s-76-16-amdt-2-main-rotor-blade-root-end-inspection-for-fatigue-cracking/history","analysis":"/api/acts/ad-s-76-16-amdt-2-main-rotor-blade-root-end-inspection-for-fatigue-cracking/analysis","conflicts":"/api/acts/ad-s-76-16-amdt-2-main-rotor-blade-root-end-inspection-for-fatigue-cracking/conflicts","importantCases":"/api/acts/ad-s-76-16-amdt-2-main-rotor-blade-root-end-inspection-for-fatigue-cracking/important-cases","documents":"/api/acts/ad-s-76-16-amdt-2-main-rotor-blade-root-end-inspection-for-fatigue-cracking/documents"}}