{"id":"F2006B08751","name":"AD/DAUPHIN/40 - Main Rotor Shaft","slug":"ad-dauphin-40-main-rotor-shaft","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52015,"registerId":"commonwealth-F2006B08751-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DAUPHIN/40 - Main Rotor 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/40 Main Rotor Shaft  7/94 DM\n\nApplicability: All model SA 365 helicopters versions C, C1, C2, C3, N, N1 and N2 equipped with main rotor shaft P/N 365A31-1179-00, -01, -02, -03, -04 or -21 with serial number\n\nless than 10000.\n\n \n\nRequirement: Action in accordance with Eurocopter France Telex Service No 01-31 or 01-39, as applicable.\n\n \n\nNote: DGAC AD 93-066-037(B)R1 and 93-065-034(B)R1 refer.\n\n \n\nCompliance: As specified in the Requirement Document.\n\n \n\nBackground: The manufacturer has advised that corrosion has been found on the mast during overhaul.\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":false,"description":"The directive defines a narrowly targeted scope (specific SA 365 variants, explicit part numbers and a serial-number cutoff) and requires compliance with manufacturer telexes. The text contains no language indicating an expansion or reduction of that scope from an earlier statement; it instead points operators to the Eurocopter telex documents for the substantive remedial measures. The notes reference related DGAC ADs but do not themselves change the applicability set out in this instrument."},"complexity_factors":["Narrow and specific applicability: limited to SA 365 variants and to specified main rotor shaft P/Ns with serial number <10000 (Applicability)","Requirement refers to external technical documents (Eurocopter Telex Service No 01-31 or No 01-39) for the substantive actions, increasing operational complexity because the AD does not itself set out procedures or timing (Requirement; Compliance)","Multiple part numbers listed create record-checking work for operators to determine applicability (Applicability)","References to other regulatory ADs (DGAC ADs) add cross‑document tracing to fully understand regulatory context (Note)","The AD does not specify cost allocation, timing or exact remedial steps — those are deferred to the manufacturer document, adding implementation dependence on an external source (Requirement; Compliance)"],"plain_english_summary":"- What the instrument changes, mechanically:\n  - The directive requires operators of certain Eurocopter Dauphin helicopters to carry out the actions set out in Eurocopter France Telex Service No 01-31 or No 01-39 (as applicable). (Requirement)\n  - It applies only to SA 365 series helicopters (versions C, C1, C2, C3, N, N1 and N2) that are fitted with a main rotor shaft having part number 365A31-1179-00, -01, -02, -03, -04 or -21 and whose shaft serial number is less than 10000. (Applicability)\n  - The timing and exact work to be done are those specified in the referenced Eurocopter telex documents; compliance is to be performed “as specified in the Requirement Document.” (Requirement; Compliance)\n\n- Why the rule is in place (official rationale stated in the instrument):\n  - The manufacturer advised that corrosion was discovered on the mast during overhaul. The directive references that manufacturer advice as the background for the required action. (Background)\n\n- Who is affected and who decides what to do:\n  - Owners/operators of the listed SA 365 helicopter models with the specified main rotor shaft part numbers and serial numbers are the parties required to follow the directive (Applicability; Requirement).\n  - The specific inspections, repairs or other actions to be performed are prescribed by the Eurocopter telex documents cited; that places the technical detail and sequencing under the manufacturer’s service instructions rather than spelled out in this directive. (Requirement)\n\n- Who bears the compliance burden and the likely nature of that burden:\n  - The directive imposes an operational and maintenance obligation on affected operators/owners to locate affected shafts and carry out the telex-prescribed work. The directive itself does not set a price or funding mechanism; the practical costs (inspection, repair, replacement, downtime) will therefore fall to those who must comply. (Applicability; Requirement; Compliance)\n\n- Incentives, trade-offs and implementation notes (mechanical effects rather than policy judgments):\n  - By referring to Eurocopter telexes, the AD centralises the technical remedy in manufacturer documents; operators must obtain and follow those documents to comply. (Requirement)\n  - The AD is targeted (specific models, part numbers and a serial-number cutoff). That narrows the set of helicopters needing immediate action but requires operators to check parts/serial records to determine applicability. (Applicability)\n  - The directive does not itself quantify the frequency, method or timing of inspections or corrective work—those details are in the telexes—so there is implementation dependence on the external requirement document. (Requirement; Compliance)\n  - The AD cites related French DGAC ADs for reference but does not, within its text, alter the applicability or the required telex actions. (Note)\n\n- Practical compliance steps an affected operator would take (inferred from the directive’s structure):\n  1. Identify whether any SA 365 helicopters under their control are fitted with the listed part numbers and check the shaft serial numbers. (Applicability)\n  2. Obtain Eurocopter France Telex Service No 01-31 or No 01-39, as applicable, and follow the procedures set out there. (Requirement; Compliance)\n  3. Record and certify the work in the aircraft’s maintenance records as required for airworthiness compliance. (Compliance — implied by the nature of airworthiness directives and the AD’s instruction to comply)\n\n- Source references within this instrument: Applicability; Requirement; Compliance; Background; Note."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific corrosion issue in a specific aircraft component. It has not expanded beyond its original purpose of mandating inspection/correction of corroded main rotor shafts in the specified Dauphin helicopter models."},"complexity_factors":["Single, narrow technical scope (one specific helicopter part)","Only 6 defined applicability criteria (model variants, part numbers, serial number threshold)","No nested conditional logic or exceptions","No cross-references to other legislation — only references to manufacturer technical documents","Straightforward compliance requirement: follow the manufacturer's telex instructions","Total length: approximately 150 words of substantive content"],"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). Think of it like a compulsory recall notice, but for aircraft parts.\n\n**What it does:** It requires owners and operators of specific Eurocopter Dauphin helicopters to take corrective action on their **main rotor shafts** (the central spinning column that connects the engine to the rotor blades). The directive applies to certain part numbers and serial numbers of rotor shafts that have been found to develop **corrosion** (rust-like damage) during maintenance overhauls.\n\n**Who must comply:** Anyone operating these specific helicopter models:\n- SA 365 C, C1, C2, C3, N, N1, and N2 versions\n- Equipped with main rotor shaft part numbers 365A31-1179-00 through -04, or -21\n- With serial numbers below 10,000\n\n**What action is required:** Operators must follow the instructions in specific Eurocopter France technical bulletins (Telex Service No. 01-31 or 01-39, depending on their situation).\n\n**Why it matters:** Corrosion in a main rotor shaft is extremely serious. The rotor shaft is critical to flight safety — if it fails, the helicopter loses lift and control. This AD prevents potential catastrophic accidents by catching corrosion before it becomes dangerous.\n\n**Key point:** This is **not optional**. Compliance is legally mandatory, and the timeframe is set by the referenced technical documents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-40-main-rotor-shaft","history":"/api/acts/ad-dauphin-40-main-rotor-shaft/history","analysis":"/api/acts/ad-dauphin-40-main-rotor-shaft/analysis","conflicts":"/api/acts/ad-dauphin-40-main-rotor-shaft/conflicts","importantCases":"/api/acts/ad-dauphin-40-main-rotor-shaft/important-cases","documents":"/api/acts/ad-dauphin-40-main-rotor-shaft/documents"}}