{"id":"F2009L01766","name":"AD/DAUPHIN/99 - Fuel Crossfeed High Level Switches","slug":"ad-dauphin-99-fuel-crossfeed-high-level-switches","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":78690,"registerId":"commonwealth-F2009L01766-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter SA 360 and SA 365 (Dauphin) S","sectionType":"division","heading":"Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters","content":"### Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters\n\n| AD/DAUPHIN/99 | Fuel Crossfeed High Level Switches | 7/2009 TX |\n| ------------- | ---------------------------------- | --------- |\n\n| Applicability: | SA 365 N and SA 365 N1 helicopters, all serial numbers, except those incorporating modification kit 365A087690.00 or modification 0728B17 (removal of the two high level switches from helicopters equipped with a crossfeed between the fuel filler necks). |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement: | 1. Disconnect the fuel high level switches in accordance with the instructions of paragraph 2.B.1 of Eurocopter AS365 Alert Service Bulletin (ASB) 01.00.63. |\n| | 2. On helicopters not equipped with a crossfeed between the fuel filler necks, install a placard near the fuel panel in accordance with the instructions of paragraph 2.B.2 of Eurocopter AS365 ASB 01.00.63 dated 5 May 2009. |\n| | Later revisions of ASB 01.00.63 approved by the European Aviation Safety Agency are acceptable for compliance with this Directive. |\n| | Note: EASA Emergency AD 2009-0109-E refers. |\n| Compliance: | For Requirements 1 and 2 - Within 10 hours time in service or 30 days, whichever occurs first after the effective date of this Directive. |\n| | This Airworthiness Directive becomes effective on 8 May 2009. |\n| Background: | One SA 365 N operator noted that the high level switch probe unit, located in the rear (right hand) auxiliary fuel tank group had separated. This caused damage to the insulation of the electrical wires which supply the high level indicator light on the fuel control panel during a fuel transfer.This condition, if not detected and corrected, could lead to exposure of the electrical wires, potentially causing a short circuit and subsequent lighting of the indicator light without the high fuel level actually being reached. In addition, a short circuit could become a potential ignition source inside the fuel tank which, in combination with flammable fuel vapours (if present), could result in a fuel tank explosion and consequent loss of the helicopter. |\n\n| | For the reasons described above, this Directive requires the disconnection of the high level switches on the affected helicopters. Disconnecting the switches inhibits the high (fuel) level warning system which normally informs the flight crew of the risk of fuel overflowing from the tank vents. To mitigate that risk, this Directive also requires, for certain helicopters, the installation of a placard near the fuel panel, limiting the transfer of fuel between fuel tank groups to cases where the receiving fuel tank group contains less than 300 litres (240 kg or 529 lbs).This Directive is considered to be a temporary measure and further rulemaking is likely to follow. |\n| --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n8 May 2009","sortOrder":0},{"sectionNumber":"AD/DAUPHIN/99","sectionType":"part","heading":"AD/DAUPHIN/99","content":"## AD/DAUPHIN/99","sortOrder":1},{"sectionNumber":"Fuel Crossfeed High Level Switches","sectionType":"part","heading":"Fuel Crossfeed High Level Switches","content":"## Fuel Crossfeed High Level Switches","sortOrder":2},{"sectionNumber":"7/2009 TX","sectionType":"part","heading":"7/2009 TX","content":"## 7/2009 TX","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive implements a targeted safety mitigation consistent with the stated problem: disconnect faulty high level switches and, where relevant, add a placard restricting fuel transfer to receiving tanks under 300 litres. The text shows no expansion or narrowing of that scope beyond the original corrective action and the stated exception for previously modified helicopters."},"complexity_factors":["Technical intervention: physical disconnection of high level switch probes and potential wiring work.","Applicability carve-out: exclusion for helicopters with modification kit 365A087690.00 or modification 0728B17.","Conditional mitigation: placard required only for helicopters lacking a filler-neck crossfeed.","Operational trade-off: disables an automatic warning system and imposes a manual operational limit (300 litres).","Reference to external documents: compliance depends on following Eurocopter AS365 Alert Service Bulletin 01.00.63 (and EASA-approved revisions).","Short compliance window: work required within 10 hours time in service or 30 days.","Temporary measure flagged: directive described as interim, with further rulemaking likely."],"plain_english_summary":"This Airworthiness Directive requires operators of Eurocopter SA 365 N and N1 helicopters (except those with a specific modification) to disconnect the fuel tank high level switches and, for helicopters without a filler-neck crossfeed, fit a placard limiting fuel transfers to receiving tanks under 300 litres. Mechanically, it removes an automatic high-level warning (to eliminate an ignition/short-circuit risk) and replaces it with an operational restriction; compliance is required within 10 flight hours or 30 days."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a targeted emergency safety directive addressing a specific mechanical defect. The scope remains precisely focused on the fuel switch defect and associated explosion risk. The temporary nature of the fix and reference to future rulemaking are standard for aviation safety directives and do not represent scope creep."},"complexity_factors":["Short, single-purpose directive with only 2 substantive requirements","Limited applicability — specific to 2 helicopter models with clear serial number exceptions","Simple conditional logic ( Requirement 2 only applies to helicopters without crossfeed systems)","Single external reference to Eurocopter service bulletin ASB 01.00.63","No nested definitions or extensive interpretation sections","Background and reasoning clearly explained in plain language","Compliance deadline is straightforward (10 hours/30 days)"],"plain_english_summary":"Owners and operators of Eurocopter Dauphin SA 365 N/N1 helicopters must disconnect certain rear auxiliary-tank high-level fuel switches that can break loose, short wiring and risk an in‑tank explosion. Modified helicopters with the retrofit kits are excluded.\n\nThis emergency AD also requires a cockpit placard and fuel-transfer limit as a manual safeguard, must be done within 10 flight hours or 30 days of 8 May 2009, and is a temporary safety fix pending a permanent solution."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-99-fuel-crossfeed-high-level-switches","history":"/api/acts/ad-dauphin-99-fuel-crossfeed-high-level-switches/history","analysis":"/api/acts/ad-dauphin-99-fuel-crossfeed-high-level-switches/analysis","conflicts":"/api/acts/ad-dauphin-99-fuel-crossfeed-high-level-switches/conflicts","importantCases":"/api/acts/ad-dauphin-99-fuel-crossfeed-high-level-switches/important-cases","documents":"/api/acts/ad-dauphin-99-fuel-crossfeed-high-level-switches/documents"}}