{"id":"F2006B08756","name":"AD/DAUPHIN/45 - Transmission Deck Beams","slug":"ad-dauphin-45-transmission-deck-beams","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52025,"registerId":"commonwealth-F2006B08756-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DAUPHIN/45 - Transmission Deck Beams","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nEurocopter SA 360 and SA 365 (Dauphin) Series Helicopters\n\nAD/DAUPHIN/45 Transmission Deck Beams 10/95\n\nDM\n\nApplicability: Model SA365 helicopters versions N, N1, N2, F, Fs and K.\n\nRequirement: Visually inspect the upper and lower surfaces of the transmission deck and the beams at X 3826.7 and X 4338.7 under the transmission deck. Inspect for cracking in accordance with Eurocopter Telex Service No 01.41.\n\nNote: DGAC AD 95-067-038(B) refers.\n\nCompliance: For models N, N1, F, Fs and K, inspect before 4000 hours time in service or before 50 hours time in service after 17 August 1995, whichever occurs later. For model N2, inspect before 2000 hours time in service or before 50 hours time in service after 4 August 1995, whichever occurs later.\n\nBackground: Cracks have been found in one of the two support beams under the transmission deck and on the transmission deck. Extensive cracking could result in loss of structural integrity of the transmission deck.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive sets an initial, narrowly targeted inspection requirement for specified SA365 models and specifies compliance timings. The text does not indicate any alteration or expansion of scope from a prior instrument within this document; it states the affected models, inspection locations and timing requirements without describing a change from earlier coverage. (Applicability; Requirement; Compliance)"},"complexity_factors":["Narrow technical scope confined to specific helicopter models and defined structural locations (X 3826.7 and X 4338.7). (Applicability; Requirement)","Two different compliance schedules: one for model N2 and a second for the other listed models, with hour-based thresholds and short-term 50-hour windows tied to specific dates. (Compliance)","Procedural detail delegated to an external document (Eurocopter Telex Service No 01.41), creating reliance on a separate technical publication for inspection method. (Requirement)","Reference to an external regulator’s AD (DGAC AD 95-067-038(B)), indicating cross-jurisdictional coordination but not additional procedural content in this instrument. (Note)","Lack of in-text repair criteria or follow-up procedure in the AD itself — the AD mandates inspection but relies on the telex for how to carry out inspections and, implicitly, corrective actions. (Requirement)"],"plain_english_summary":"The Civil Aviation Safety Authority requires owners/operators of Eurocopter SA365 (Dauphin) variants N, N1, N2, F, Fs and K to carry out a visual inspection of the transmission deck upper/lower surfaces and two supporting beams at specified locations, following Eurocopter Telex Service No. 01.41. The inspections must be done by set hours‑in‑service thresholds (before 4,000 TIS for N/N1/F/Fs/K; before 2,000 TIS for N2, with short 50‑hour grace periods). Costs and any repairs are the operator’s responsibility."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific safety-critical structural defect in defined helicopter models. It has not expanded beyond its original purpose of mandating inspections for transmission deck cracking."},"complexity_factors":["Single, specific mechanical issue (transmission deck cracking)","Limited applicability (6 specific helicopter model variants)","Straightforward inspection requirement with reference to external technical standard (Eurocopter Telex Service No 01.41)","Simple conditional compliance: two alternative deadlines per model group (flight hours OR calendar-based hours)","No nested exceptions or complex cross-referencing within the instrument itself","Background explanation provided in plain language"],"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 as a \"recall notice\" for aircraft, but legally binding.\n\n**What it does:** It requires owners and operators of specific Eurocopter Dauphin helicopters to visually inspect the transmission deck (the structure that holds the main rotor gearbox) and two support beams underneath it for cracks.\n\n**Who it affects:** Operators of Eurocopter SA 365 helicopter models N, N1, N2, F, Fs, and K.\n\n**Why it matters:** Cracks have been discovered in these components. If left unchecked, extensive cracking could cause the transmission deck to fail structurally — potentially leading to catastrophic loss of the helicopter. The directive sets strict deadlines for these inspections based on flight hours and dates.\n\n**Key deadlines:**\n- For most models (N, N1, F, Fs, K): Inspect before reaching 4,000 flight hours OR within 50 flight hours after 17 August 1995, whichever comes later\n- For model N2: Inspect before 2,000 flight hours OR within 50 flight hours after 4 August 1995, whichever comes later"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-45-transmission-deck-beams","history":"/api/acts/ad-dauphin-45-transmission-deck-beams/history","analysis":"/api/acts/ad-dauphin-45-transmission-deck-beams/analysis","conflicts":"/api/acts/ad-dauphin-45-transmission-deck-beams/conflicts","importantCases":"/api/acts/ad-dauphin-45-transmission-deck-beams/important-cases","documents":"/api/acts/ad-dauphin-45-transmission-deck-beams/documents"}}