{"id":"F2006B02003","name":"AD/A330/25 - Auxiliary Power Unit Control Box","slug":"ad-a330-25-auxiliary-power-unit-control-box","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41225,"registerId":"commonwealth-F2006B02003-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nAirbus Industrie A330 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/A330/25 Auxiliary Power Unit Control ","sectionType":"part","heading":"AD/A330/25 Auxiliary Power Unit Control Box 12/2003","content":"# AD/A330/25 Auxiliary Power Unit Control Box 12/2003\n\nApplicability: A330 model \\-202, -203, \\-223, \\-243, \\-301, \\-321, \\-322, \\-323, \\-341, \\-342 and \\-343\n\naeroplanes, all serial numbers, except for aeroplanes with Airbus modification 50245 embodied during production or whilst in service in accordance with Airbus Industrie Service Bulletin (SB) A330- 49-3025.\n\nRequirement: Install a decoupling diode 62KD in the Auxiliary Power Unit (APU) control box 5000VE in accordance with SB A330- 49-3025.\n\nNote: DGAC AD 2003-350(B) refers.\n\nCompliance: Before 30 September 2004.\n\nThis Airworthiness Directive becomes effective on 27 November 2003.\n\nBackground: This Directive requires the installation of a decoupling diode in the APU control box. The installation of the diode is designed to prevent APU shutdown occurring during flight due to loss ‘in flight’ signal information.\n\n![](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 14 October 2003\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"No change in scope from the directive's stated purpose: it prescribes a single retrofit for the listed aircraft and excludes those already modified by Airbus mod 50245. The AD does not expand applicability beyond the listed models or add ongoing obligations beyond completing the retrofit by the specified date."},"complexity_factors":["Narrow, model-specific applicability covering listed A330 variants (Applicability).","Single, discrete technical modification (install diode 62KD) — straightforward hardware retrofit (Requirement).","Dependency on manufacturer's Service Bulletin A330-49-3025 for technical instructions and embodiment (Requirement/Note).","Explicit exemption for aircraft already modified by Airbus modification 50245 reduces scope overlap (Applicability).","Firm compliance deadline creates scheduling and cost burden for operators but no ongoing regulatory reporting (Compliance).","Safety-critical context: action addresses an in-flight shutdown risk, raising implementation and inspection importance (Background)."],"plain_english_summary":"Requires installation of a decoupling diode (62KD) in the APU control box 5000VE on specified Airbus A330 models, except aircraft already modified by Airbus modification 50245 per Service Bulletin A330-49-3025. The diode is intended to prevent in-flight APU shutdown caused by loss of the ‘in flight’ signal. Operators must complete the modification by 30 September 2004 in accordance with the Airbus service bulletin."},"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":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with a narrow, specific safety purpose. The scope remains tightly focused on the identified unsafe condition (APU shutdown risk) and the specific aircraft models affected. There is no evidence of scope creep or expansion beyond the original safety intent."},"complexity_factors":["Single, specific technical requirement (install one component)","Clear applicability section with explicit model numbers and serial number exemption","Single compliance deadline with no conditional timing","No nested definitions or cross-references to other legislation (only references a technical service bulletin)","Short document (approximately 200 words of substantive content)","Straightforward background explanation with no legal exceptions or provisos"],"plain_english_summary":"This CASA safety order requires operators of specified Airbus A330‑200/300 aircraft to install a decoupling diode in the APU control box (per Airbus Service Bulletin A330‑49‑3025) unless the Airbus factory modification is already fitted. The fix prevents unintended in‑flight APU shutdown from a lost airborne signal, protecting electrical/system availability. Compliance deadline: before 30 September 2004."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a330-25-auxiliary-power-unit-control-box","history":"/api/acts/ad-a330-25-auxiliary-power-unit-control-box/history","analysis":"/api/acts/ad-a330-25-auxiliary-power-unit-control-box/analysis","conflicts":"/api/acts/ad-a330-25-auxiliary-power-unit-control-box/conflicts","importantCases":"/api/acts/ad-a330-25-auxiliary-power-unit-control-box/important-cases","documents":"/api/acts/ad-a330-25-auxiliary-power-unit-control-box/documents"}}