{"id":"F2006B08758","name":"AD/DAUPHIN/47 - Single Pole Circuit Breakers","slug":"ad-dauphin-47-single-pole-circuit-breakers","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52029,"registerId":"commonwealth-F2006B08758-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DAUPHIN/47 - Single Pole Circuit Breakers","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/47 Single Pole Circuit Breakers 6/98\n\nApplicability: Model SA 360 and SA 365 helicopters versions C, C1, C2 and C3 fitted with single pole circuit breakers manufactured by CROUZET bearing the following part numbers:\n\n| Circuit Breaker Rating | Part Number | Circuit Breaker Rating | Part Number |\n| ---------------------- | ----------- | ---------------------- | ----------- |\n| 1 Amp                  | 84 400 028  | 7.5 Amp                | 84 400 033  |\n| 2 Amp                  | 84 400 029  | 10 Amp                 | 84 400 034  |\n| 2.5 Amp                | 84 400 030  | 15 Amp                 | 84 400 035  |\n| 3 Amp                  | 84 400 031  | 20 Amp                 | 84 400 036  |\n| 5 Amp                  | 84 400 032  | 25 Amp                 | 84 400 037  |\n\nNote: Two types of CROUZET circuit breakers may have been delivered under Eurocopter part number(PN) 704A36-6120-XX:\n\nCircuit breaker CROUZET PN 84 400 XXX, or Circuit breaker CROUZET PN SP4696-XX.\n\nThis directive is only applicable to circuit breakers CROUZET PN 84 400 XXX.\n\nRequirement: 1\\. Check, in accordance with paragraph 2 B of Eurocopter SA 360/365 Mandatory Service Bulletin No 01.36 dated 11 December 1997, all circuit breakers listed in the above table, which are fitted in systems referenced in paragraph 1 D 1 of the same service bulletin.\n\n    2. Check, in accordance with paragraph 2 B of the referenced service bulletin, the circuit breakers in the above table fitted in the remaining systems.\n\n    3. Test each CROUZET circuit breaker, held as a spare and bearing a part number listed in the above table, in accordance with paragraphs 2 B (1) and 2 B (2) of the referenced service bulletin.\n\n    4. The use of a circuit breaker bearing a part number listed in the above table is prohibited.\n\nNote: DGAC AD 98-112-042(A) refers.\n\nCompliance: 1\\. Within 100 hours time in service after 21 May 1998, but no later than 21 August 1998.\n\n    2. Within 500 hours time in service after 21 May 1998, but no later than 21 November 1998.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n    3. Prior to installation.\n\n    4. After 31 December 1999.\n\nThis airworthiness directive becomes effective on 21 May 1998.\n\nBackground: This directive is issued to check for any loss of electrical continuity for single pole circuit breakers. Eurocopter has reported that during testing a loss of electrical continuity was discovered between the terminals of the circuit breaker in the engaged position. This loss was found to be due to deterioration of the circuit breaker operation brought about by excessive torque loading during installation.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive remains narrowly focused on identifying, testing and eventually prohibiting specific CROUZET single‑pole circuit breakers on designated SA 360/365 helicopter models. It enforces a manufacturer test procedure and sets compliance deadlines; it does not broaden the subject matter beyond the original safety problem (loss of electrical continuity in the listed circuit breakers)."},"complexity_factors":["Short, single‑issue airworthiness directive focused on one component type","12 CROUZET part numbers listed (84 400 028 to 84 400 037)","Cross‑reference to an external Eurocopter Mandatory Service Bulletin (paragraph 2B) for test procedures","Two compliance timing bands (100 hours / 500 hours) plus requirement for testing spares prior to installation","Prohibition on use of listed part numbers after a specified date (31 Dec 1999)","Note that a single Eurocopter part number may correspond to two different CROUZET part number families, requiring part‑level verification"],"plain_english_summary":"**What this instrument does (mechanically):**\n\n- Applies to Eurocopter (Aérospatiale) SA 360 and SA 365 (Dauphin) helicopters, versions C, C1, C2 and C3, when fitted with specific single‑pole circuit breakers manufactured by CROUZET with part numbers 84 400 028 through 84 400 037 (various amp ratings) (see \"Applicability\").\n\n- Requires operators to inspect and test those CROUZET circuit breakers in two groups of systems and to test spares, using the procedures set out in Eurocopter SA 360/365 Mandatory Service Bulletin No 01.36 (paragraph 2B) (\"Requirement\" items 1–3).\n\n- Prohibits the use of any circuit breaker bearing any of the listed CROUZET part numbers after 31 December 1999 (\"Requirement\" item 4 and \"Compliance\" item 4).\n\n- Sets mandatory time limits for when inspections and tests must be completed: first group within 100 flight hours (but no later than 21 August 1998), second group within 500 flight hours (but no later than 21 November 1998), and spares must be tested before installation (see \"Compliance\").\n\n**Who is affected:**\n\n- Owners and operators of the specified SA 360/SA 365 Dauphin helicopters that carry the listed CROUZET single‑pole circuit breakers.\n- Maintenance organisations and technicians who perform inspections, tests and replacements for these helicopters.\n- Parts suppliers and spare stock managers who hold or supply the listed CROUZET part numbers.\n\n**Why it matters (stated purpose and operational effect):**\n\n- The directive follows Eurocopter testing that found some CROUZET single‑pole breakers could lose electrical continuity (stop conducting current) when in the engaged (on) position; the problem was linked to deterioration caused by excessive torque during installation (see \"Background\").\n- Mechanically, the AD forces operators to identify, inspect and test the listed breakers, to remove any unreliable items from service, and to stop using those listed part numbers after the specified date. The safety objective is to reduce the risk that a breaker wrongly opens (or fails to close) because of internal loss of continuity.\n\n**How it works in practice (who pays, who decides, what changes):**\n\n- Who decides: The Civil Aviation Safety Authority (CASA) issues and enforces the directive; the detailed test and inspection method is delegated to Eurocopter's Mandatory Service Bulletin No 01.36 (paragraph 2B), which the AD makes mandatory.\n- Who pays: aircraft owners/operators pay for the inspections, testing, labour and any replacement parts or removal/installation costs. Maintenance organisations absorb technician time and test equipment use.\n- Behaviour changes required from operators: locate and identify whether affected breakers are fitted (note: Eurocopter PN 704A36‑6120‑XX can correspond to two different CROUZET part number families, so technicians must check the CROUZET PN, not just the Eurocopter PN); perform the mandatory checks and tests within the stated time windows; test any listed spare before installation; and stop installing or using any listed CROUZET part number after 31 Dec 1999.\n\n**Practical implementation notes and trade‑offs:**\n\n- The AD cross‑references Eurocopter Mandatory Service Bulletin No 01.36 for test procedures (the AD does not reproduce test steps). That means compliance requires access to and correct interpretation of the service bulletin.\n- Compliance imposes direct costs: inspection/test labour, possible replacement parts if breakers fail, and administrative time to track spares and installation controls.\n- Supply and substitution effects: operators who must remove listed breakers will need acceptable replacement breakers; this may increase demand for compliant parts and could create short‑term procurement or stocking costs.\n- Enforcement and compliance risk: CASA will determine acceptability of compliance; improper identification of parts (because a Eurocopter PN could correspond to two CROUZET families) is an implementation risk that could lead to inadvertent non‑compliance.\n- Concentrated benefits and diffuse costs: the safety benefit concentrates on aircraft occupants and those affected by an in‑flight electrical failure; the compliance cost is borne directly by the smaller group of owners/operators of the specified helicopter models and by suppliers of the listed parts.\n\n**Source claims vs. costs and incentives:**\n\n- The AD cites manufacturer testing discovering loss of continuity due to deterioration from excessive installation torque. Making the manufacturer test procedure mandatory is intended to detect compromised breakers before failure (stated purpose). The cost of those tests and any replacement parts is borne by operators; the AD does not provide financial assistance or part replacement relief. The AD shifts purchasing and inventory incentives toward breakers not bearing the listed CROUZET part numbers (Requirement item 4)."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope: addressing a specific manufacturing defect in specific circuit breakers on specific helicopter models. There is no evidence of scope creep; it remains a targeted safety intervention."},"complexity_factors":["Multiple compliance deadlines (4 separate timelines based on system criticality and use case)","Cross-reference to external technical document (Eurocopter Mandatory Service Bulletin No 01.36) without reproducing its contents","Specific part number identification requiring careful matching against aircraft records","Exception note clarifying that similar-looking part numbers (SP4696-XX) are excluded from this directive","Nested applicability criteria (specific helicopter models + specific versions + specific manufacturer + specific part number range)"],"plain_english_summary":"This CASA safety order applies to Eurocopter SA 360/365 Dauphin helicopters using CROUZET single‑pole circuit breakers (part numbers beginning \"84 400\"). It requires owners/operators to inspect and test affected breakers (including spares), with staged inspection intervals and a prohibition on their use after 31 December 1999.\n\nThe action responds to an internal failure mode—breakers can lose electrical connection even when \"on\"—which risks sudden loss of critical flight systems."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-47-single-pole-circuit-breakers","history":"/api/acts/ad-dauphin-47-single-pole-circuit-breakers/history","analysis":"/api/acts/ad-dauphin-47-single-pole-circuit-breakers/analysis","conflicts":"/api/acts/ad-dauphin-47-single-pole-circuit-breakers/conflicts","importantCases":"/api/acts/ad-dauphin-47-single-pole-circuit-breakers/important-cases","documents":"/api/acts/ad-dauphin-47-single-pole-circuit-breakers/documents"}}