{"id":"F2006B08737","name":"AD/DAUPHIN/26 Amdt 1 - Tail Rotor Control Shaft","slug":"ad-dauphin-26-amdt-1-tail-rotor-control-shaft","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51975,"registerId":"commonwealth-F2006B08737-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DAUPHIN/26 Amdt 1 - Tail Rotor Control Shaft","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)  Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters\n\n \n\nAD/DAUPHIN/26\n\nAmdt 1\n\n\nTail Rotor Control Shaft 1/92\n\n \n\nApplicability: All model SA 360, 365C, C1, C2, C3, N and FS Helicopters. Requirement:  Action in accordance with Aerospatiale SB 05.15 or 05.24, as applicable.\n\nNote: D6AC AD 90-204-033(B) refers to SB 05.15 only.\n\n \n\nCompliance: As specified in the Requirement document.\n\n \n\nBackground:  Excessive wear of the tail rotor control shaft bearings could result in loss of tail rotor control. This amendment extends the Requirement to all 365 series helicopters.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"The original AD (issued as 1/92) applied to a subset of Dauphin helicopters. Amendment 1 explicitly extends the requirement to 'all 365 series helicopters,' broadening the scope beyond the original applicability. This is a modest expansion rather than a fundamental shift in purpose — the safety issue remains the same (tail rotor control shaft bearing wear), but the regulatory net is cast wider to capture more aircraft variants."},"complexity_factors":["Very short document (approximately 200 words)","Only 1 defined term implicitly referenced (the service bulletins SB 05.15 and SB 05.24)","No nested conditional logic or cross-references to other legislation","Simple structure: applicability, requirement, compliance, background","Single amendment extending scope to additional helicopter models","Relies on external technical documents (service bulletins) for actual implementation details rather than containing technical specifications within the text"],"plain_english_summary":"This is an **Airworthiness Directive** (AD) — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for specific helicopter models.\n\n**What it does:**\n- Requires owners and operators of certain Eurocopter Dauphin helicopters to inspect or fix a problem with the **tail rotor control shaft bearings**\n- The bearings can wear out excessively, which could cause the pilot to lose control of the tail rotor — a critical safety issue that could lead to loss of control of the aircraft\n\n**Who it affects:**\n- All Eurocopter (now Airbus Helicopters) **SA 360** and **SA 365** series helicopters, including models C, C1, C2, C3, N, and FS variants\n- This amendment (Amendment 1) expands the original directive to cover **all** SA 365 series helicopters, not just some of them\n\n**What must be done:**\n- Operators must follow the instructions in specific manufacturer service bulletins: **SB 05.15** or **SB 05.24** (depending on which applies to their aircraft)\n- The timing and method of compliance are set out in those service bulletins\n\n**Why it matters:**\n- Tail rotor failure or loss of control is extremely dangerous in helicopters — it can cause the aircraft to spin uncontrollably\n- This directive prevents accidents by catching bearing wear before it becomes critical"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The AD explicitly states that this amendment \"extends the Requirement to all 365 series helicopters\" (\"Background\"). That is a change in scope from the previous arrangement, which (as noted) included an earlier AD referencing only SB 05.15. The amendment therefore increases the set of affected aircraft by including all SA 365 variants listed under \"Applicability\"."},"complexity_factors":["Relies on external technical documents (Aerospatiale SB 05.15 or SB 05.24) for the exact inspection/repair steps and timing, so the AD does not contain operational detail (\"Requirement\" and \"Compliance\").","Applicability covers multiple models (SA 360 and a range of SA 365 variants), requiring operators to determine which Service Bulletin applies to their variant (\"Applicability\" and \"Note\").","Cross-reference to a prior AD (D6AC AD 90-204-033(B)) which referenced only one Service Bulletin introduces an additional document-tracing step (\"Note\").","Regulatory context (Civil Aviation Regulations 1998, PART 39) creates compliance obligations enforceable by the Civil Aviation Safety Authority; the AD itself is short and procedural rather than descriptive (header and \"Compliance\").","Safety-critical mechanical subject matter (tail rotor control shaft bearings) requires technical expertise to assess and implement, even though the AD text is brief (\"Background\")."],"plain_english_summary":"# What this directive does\n\nThis Airworthiness Directive (AD/DAUPHIN/26 Amdt 1) tells owners and operators of certain Eurocopter (Aerospatiale) Dauphin helicopters to take specific maintenance actions on the tail rotor control shaft. Mechanically, it requires operators to carry out the inspections/repairs set out in the manufacturer's Service Bulletins (Aerospatiale SB 05.15 or SB 05.24), because excessive wear of the tail rotor control shaft bearings can lead to loss of tail rotor control. (See \"Applicability\", \"Requirement\" and \"Background\".)\n\n# Who it affects\n\n- Operators and owners of all model SA 360 and SA 365 (C, C1, C2, C3, N and FS) helicopters. (See \"Applicability\".)\n- Maintenance organisations and technicians who perform the required actions under the relevant Aerospatiale service bulletin(s). (See \"Requirement\".)\n\n# How it works mechanically\n\n- The AD points to the Aerospatiale Service Bulletin(s) as the working instructions: SB 05.15 or SB 05.24, as applicable. Operators must carry out the actions set out in those documents. (See \"Requirement\" and \"Compliance\".)\n- The AD’s compliance timing and specific procedures are defined in the referenced Service Bulletin(s) and in the Requirement document. The AD itself does not restate step-by-step procedures. (See \"Requirement\" and \"Compliance\".)\n\n# Why it matters (official rationale and practical effects)\n\n- Official rationale: excessive wear of tail rotor control shaft bearings could result in loss of tail rotor control. The AD is issued to address that safety risk. (See \"Background\".)\n\n- Practical effects and trade-offs:\n  - Who pays: operators/owners of the affected helicopters pay for any inspections, parts and labour required by the Service Bulletin(s). (See \"Applicability\" and \"Requirement\".)\n  - Compliance burden: the AD requires following the manufacturer's Service Bulletin(s). The AD states only that compliance must be \"as specified in the Requirement document,\" so operators must obtain and rely on those external documents to know exact tasks and timing. (See \"Requirement\" and \"Compliance\".)\n  - Decision authority: the Civil Aviation Safety Authority issued this AD under the Civil Aviation Regulations framework (PART 39), and operators must follow it. The AD points to Aerospatiale documents for the technical content. (See header and \"Requirement\".)\n  - Effects on maintenance market and competition: maintenance work will be driven by the Service Bulletin instructions. Independent maintenance providers may perform the required actions, subject to regulatory approvals and the technical steps in the Service Bulletin(s). The AD does not itself restrict who may perform the work; it specifies the actions to be done. (See \"Requirement\".)\n  - Implementation risk and operational impact: the AD extends the requirement to all 365 series helicopters (expanding the set of affected aircraft), which increases the number of operators that will incur inspection/repair costs and potential aircraft downtime. (See \"Background\".)\n\n# Cross-references and clarifications\n\n- The AD references two possible Aerospatiale Service Bulletins (SB 05.15 or SB 05.24) \"as applicable\"; one earlier AD (D6AC AD 90-204-033(B)) referred only to SB 05.15. Operators must check which SB applies to their specific model/configuration. (See \"Requirement\" and \"Note\".)\n\n# Net summary\n\nThis AD imposes a regulatory requirement on operators of the listed Dauphin models to carry out manufacturer-prescribed inspections/repairs to the tail rotor control shaft bearings to reduce the risk of loss of tail rotor control. The direct costs fall on aircraft owners/operators and on whoever performs the maintenance. The AD defers technical detail to the referenced Aerospatiale Service Bulletin(s) and requires compliance \"as specified\" in the Requirement documents. (See \"Applicability\", \"Requirement\", \"Compliance\" and \"Background\".)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-26-amdt-1-tail-rotor-control-shaft","history":"/api/acts/ad-dauphin-26-amdt-1-tail-rotor-control-shaft/history","analysis":"/api/acts/ad-dauphin-26-amdt-1-tail-rotor-control-shaft/analysis","conflicts":"/api/acts/ad-dauphin-26-amdt-1-tail-rotor-control-shaft/conflicts","importantCases":"/api/acts/ad-dauphin-26-amdt-1-tail-rotor-control-shaft/important-cases","documents":"/api/acts/ad-dauphin-26-amdt-1-tail-rotor-control-shaft/documents"}}