{"id":"F2006B06706","name":"AD/S-76/24 - Rotor Brake Installation - Modification","slug":"ad-s-76-24-rotor-brake-installation-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114519,"registerId":"commonwealth-F2006B06706-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/S-76/24 - Rotor Brake Installation - Modification","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-76/24 Rotor Brake Installation - Modification 10/82\n\nApplicability: All models S-76A.\n\n \n\nRequirement: Modify the rotor brake system by incorporation of the following Sikorsky documents: 1. CSB 76-66-7.\n\n2. CSB 76-66-8A.\n\n \n\n3. CSB 76-66-10B.\n\n \n\n4. CSN 76-51B.\n\n \n\nNote: FAA AD 82-17-03 refers.\n\n \n\nCompliance: Within 100 hours time in service after 31 October, 1982.\n\n \n\nBackground: The manufacturer has introduced a number of modifications to the rotor brake system to reduce the possibility of brake drag and overheating.\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":2,"scope_assessment":{"changed":false,"description":"The instrument does not expand or narrow the group of affected aircraft beyond those explicitly identified: all Sikorsky S-76A models. It prescribes a specific modification (incorporation of four Sikorsky documents) and a fixed compliance window. There is no indication in the text that the directive alters broader operational or regulatory scope beyond that specific modification requirement (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow applicability: applies only to Sikorsky S-76A models (Applicability).","Single, prescriptive action: incorporation of four specified Sikorsky documents (Requirement).","Short, concrete compliance timeline: within 100 hours time in service after a specified date (Compliance).","Dependence on external technical documents: operators must obtain and follow four Sikorsky service documents (Requirement).","Cross-reference to a foreign regulator's AD (FAA), which may require consultation of additional material (Note)."],"plain_english_summary":"What this instrument does\n\n- This is an Airworthiness Directive issued under the Commonwealth aviation regulations by the Civil Aviation Safety Authority (CASA). (COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY)\n- It requires a specific mechanical change to helicopters: all Sikorsky S-76A helicopters must have their rotor brake system modified by incorporating four specified Sikorsky service documents. (Applicability; Requirement)\n\nWho it affects\n\n- The requirement applies to owners/operators of Sikorsky S-76A helicopters. (Applicability)\n- CASA is the issuing regulator that enforces the directive. (header information)\n\nWhat must be done, and by when\n\n- Operators must carry out the modification described in Sikorsky documents CSB 76-66-7, CSB 76-66-8A, CSB 76-66-10B and CSN 76-51B. (Requirement)\n- The modification must be completed within 100 hours time in service after 31 October 1982. (Compliance)\n\nWhy the change was ordered (the official rationale)\n\n- The stated reason is that the manufacturer has introduced a number of modifications to the rotor brake system to reduce the possibility of brake drag and overheating. (Background)\n- The directive also notes a related FAA airworthiness directive: FAA AD 82-17-03. (Note)\n\nPractical effects and mechanics\n\n- Who pays: owners/operators of affected S-76A helicopters will bear the direct costs of parts, labour and any associated downtime required to incorporate the four Sikorsky documents. (Applicability; Requirement; Compliance)\n- What decisions are imposed: CASA requires compliance with the specified Sikorsky service documents; it does not in this text delegate alternative compliance options or exemptions. (Requirement; Compliance)\n- Behaviour change required: maintenance programmes and work schedules must be adjusted so the rotor-brake modifications are fitted within the 100-hour window after 31 October 1982. Aircraft may need to be taken out of service until modification is complete. (Compliance)\n\nCosts, incentives, trade-offs and implementation considerations\n\n- Costs and resource trade-offs: operators will incur parts and labour costs and aircraft downtime; these are the immediate, measurable costs required to meet the directive. (Requirement; Compliance)\n- Safety incentive: implementing the specified changes is intended to decrease the risk of brake drag and overheating, which creates an operational incentive for operators to comply. (Background)\n- Opportunity cost: time, hangar space and maintenance capacity used for these modifications cannot be used for other work during the compliance window. (Compliance)\n- Implementation risk and compliance burden: the directive references four specific Sikorsky documents; operators will need access to those documents and any associated parts or tooling to complete the work. The text does not specify alternative means of compliance or a process for CASA exemptions in this document. (Requirement; Compliance)\n- Regulatory cross-reference: the AD cites an FAA directive, which may affect parts, procedures or references used by operators who consult multiple jurisdictions' guidance. (Note)\n\nLimits of what the text says\n\n- The directive prescribes which Sikorsky documents to incorporate and the compliance deadline, but it does not quantify costs, define acceptable alternative methods of compliance in this text, nor set out enforcement penalties or procedures. (Requirement; Compliance)\n\nSource citations\n\n- Issuing authority and legal basis: header of the document. (COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY)\n- Applicability: \"All models S-76A.\" (Applicability)\n- Requirement: lists the four Sikorsky documents to be incorporated. (Requirement)\n- Compliance: \"Within 100 hours time in service after 31 October, 1982.\" (Compliance)\n- Background: rationale about brake drag and overheating. (Background)\n- Related foreign directive: FAA AD 82-17-03. (Note)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive focused specifically on rotor brake modifications for one helicopter series. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Single, specific aircraft model affected (S-76A only)","Straightforward requirement: install four listed service bulletins","Simple compliance deadline (100 hours after fixed date)","No nested conditions, exceptions, or cross-references to other legislation","Minimal defined terms (only standard aviation terminology)","Short document (approximately 150 words of substantive content)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:**\nOrders owners and operators of **Sikorsky S-76A helicopters** to upgrade the rotor brake system by installing four specific manufacturer service bulletins (technical documents that describe safety fixes).\n\n**Why it matters:**\nThe original rotor brake design had a problem where the brake could \"drag\" (not fully release) and overheat. This creates fire risk and could damage the helicopter. The directive mandates a fix to prevent accidents.\n\n**Who must comply:**\nAnyone operating an S-76A helicopter in Australia.\n\n**Deadline:**\nThe modification had to be completed within **100 flight hours** after 31 October 1982.\n\n**Key point:** This is not optional — Airworthiness Directives are legally binding. Flying without complying can ground an aircraft or result in penalties."}},"importantCases":[],"_links":{"self":"/api/acts/ad-s-76-24-rotor-brake-installation-modification","history":"/api/acts/ad-s-76-24-rotor-brake-installation-modification/history","analysis":"/api/acts/ad-s-76-24-rotor-brake-installation-modification/analysis","conflicts":"/api/acts/ad-s-76-24-rotor-brake-installation-modification/conflicts","importantCases":"/api/acts/ad-s-76-24-rotor-brake-installation-modification/important-cases","documents":"/api/acts/ad-s-76-24-rotor-brake-installation-modification/documents"}}