{"id":"F2006B01891","name":"AD/A320/145 - Transformer Rectifier Unit","slug":"ad-a320-145-transformer-rectifier-unit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41087,"registerId":"commonwealth-F2006B01891-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\n![](image.001.png)  \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 CAR 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\nAirbus Industrie A319, A320 and A321 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/A320/145 Transformer Rectifier Unit 1","sectionType":"part","heading":"AD/A320/145 Transformer Rectifier Unit 13/2002","content":"# AD/A320/145 Transformer Rectifier Unit 13/2002\n\nApplicability: Airbus model A319, A320 and A321 series aeroplanes without Airbus modification 30737 incorporated during production or either Airbus Industrie Service Bulletin (SB) A320-24-1099 dated 5 March 2002 or A320-24-1099 Revision 1 dated 26 July 2002 embodied.\n\nRequirement: 1. Replace the Kollmorgen Artus transformer rectifier unit (TRU) part number (P/N) Y005-2 installed in position 2 (1PU2) by TRU P/N Y005-3 in accordance with SB A320-24-1099 Revision 1.\n\n2. TRU P/N Y005-2 may not be installed in position 2 (1PU2) as a replacement part.\n\nNote: DGAC AD 2002-554(B) refers.\n\nCompliance: For Requirement 1 \\- Either before 31 March 2004 or before the TRU has accumulated 15,000 hours’ time in service, whichever occurs later.\n\nFor Requirement 2 \\- After 31 March 2004.\n\nThis Airworthiness Directive becomes effective on 26 December 2002.\n\nBackground: The Direction Générale de l’Aviation Civile has received reports of smoke smells in the cockpit. Investigations have revealed that the smoke and/or smell is caused by the failure of the TRU input filter capacitors.\n\nThis Directive requires replacement of TRUs in position 2 (1PU2).\n\n![](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 18 November 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 4 December 2002.","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific unsafe condition in a specific component on specific aircraft models. There is no evidence of scope creep; it remains a targeted safety directive for the TRU input filter capacitor failure issue."},"complexity_factors":["Single, specific technical requirement (replace one part with another)","Limited applicability (three specific Airbus models, excluding those with specific modifications already applied)","Clear two-part compliance deadline (calendar date OR flight hours, whichever is later)","Only one defined term of note (TRU - Transformer Rectifier Unit)","No nested exceptions or conditional logic beyond the applicability criteria","Short document (approximately 300 words)","Straightforward cross-reference to French authority (DGAC) and Airbus service bulletin"],"plain_english_summary":"Australia’s civil aviation regulator requires operators of Airbus A319/A320/A321 aircraft to replace Kollmorgen Artus TRU P/N Y005-2 at position 2 (1PU2) with the improved P/N Y005-3 if they haven’t had factory mod 30737 or the service bulletin applied.  \n\nThe AD responds to cockpit smoke smells from failing TRU capacitors, creating a fire risk; replacement is due by 31 March 2004 or before 15,000 flight hours, and the old part is then prohibited."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD remains narrowly targeted to correct the specific unsafe condition identified (failure of TRU input filter capacitors causing smoke smells in the cockpit) by replacing TRU P/N Y005-2 in position 2. It does not broaden regulation beyond that corrective action or add unrelated obligations. Therefore the scope has not changed beyond the original safety-focused purpose described in the background."},"complexity_factors":["Short, focused instrument (single product and single corrective action)","2 operative requirements (replace part; prohibition on reinstallation)","Applicability conditional on modification 30737 or embodiment of Airbus SB (one-level exclusion)","Alternative compliance timing (date or hours-in-service, whichever later)","References to external documents: Airbus SB A320-24-1099 Revision 1 and DGAC AD (requires operators to consult those documents for technical details)","No large number of defined terms or nested exceptions"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- **Applies to:** Airbus A319, A320 and A321 aeroplanes that do not already have Airbus production Modification 30737 or that have not already had Airbus Service Bulletin (SB) A320-24-1099 (or its Revision 1) embodied. (See \"Applicability\".)\n\n- **Required actions:**\n  - **Requirement 1:** Replace any Kollmorgen Artus transformer rectifier unit (TRU) with part number Y005-2 that is installed in position 2 (labelled 1PU2) with TRU part number Y005-3, following the instructions in Airbus SB A320-24-1099 Revision 1.\n  - **Requirement 2:** After the specified compliance date, TRU part number Y005-2 must not be installed in position 2 (1PU2) as a replacement part.\n  (These are the two concrete, enforceable obligations.)\n\n- **When it must be done (Compliance):**\n  - For the replacement requirement (Requirement 1): do the replacement either before 31 March 2004 or before the affected TRU has accumulated 15,000 hours of time in service — whichever of those two events happens later.\n  - For the prohibition against installing the old part (Requirement 2): the ban takes effect after 31 March 2004.\n\n- **Why it was issued (stated reason):** Investigations reported smells of smoke in the cockpit traced to failures of the TRU input filter capacitors. The stated corrective measure is to replace the identified TRU in position 2 to eliminate that unsafe condition.\n\n**Who this affects**\n\n- Aircraft operators, owners and maintenance organisations that operate or service Airbus A319/A320/A321 aeroplanes meeting the applicability criteria. They must arrange, fund and perform the specified part replacement or ensure the alternate production modification/SB has already been embodied.\n\n- Parts suppliers and maintenance providers may be affected by demand for the replacement TRU (P/N Y005-3) and by the prohibition on installing P/N Y005-2 in position 2 after the deadline.\n\n- Maintenance planners and fleet managers must schedule the replacement within the time/usage window or incorporate Airbus modification 30737 / SB earlier if available.\n\n**Why it matters (practical implications)**\n\n- Safety: The AD targets a specific equipment fault (TRU input filter capacitors) linked to smoke/smell in the cockpit; replacing the susceptible TRU is intended to remove that failure mode.\n\n- Operational and financial impact: Operators bear the cost of parts, labour and downtime to comply. There may be short-term supply or scheduling impacts if many affected aircraft require the same replacement.\n\n- Compliance risk: Non-compliance after the dates means an aircraft would not meet the airworthiness directive, which can lead to regulatory enforcement, grounding or restrictions on operation until rectified.\n\n**Mechanisms, incentives and trade-offs (analyst’s lens)**\n\n- Who pays: aircraft operators/owners pay for the replacement TRU (P/N Y005-3) and associated maintenance hours and downtime.\n\n- Who decides: the CASA delegate issued the AD and operators must comply; operators can choose to comply by doing the SB/installation or by incorporating the listed modification earlier if available.\n\n- Behavioural change: maintenance schedules will prioritise replacing TRU P/N Y005-2 in position 2 before the stated deadline or before it reaches 15,000 service hours; organisations must avoid installing P/N Y005-2 in that position after 31 March 2004.\n\n- Costs vs benefit: the stated benefit is removal of a cockpit smoke risk; the cost is the price of parts, labour and aircraft downtime. The AD does not quantify those costs.\n\n- Market effects and concentration: demand shifts to the approved replacement TRU (P/N Y005-3) and to shops able to perform the SB. If replacement parts are supplied by a limited number of vendors, there could be short-term supply pressure or price effects.\n\n- Compliance burden and implementation risk: the AD references Airbus SB A320-24-1099 Revision 1 for detailed instructions; operators must follow that SB for the work. The AD’s alternative compliance trigger (date or 15,000 hours, whichever is later) requires each operator to monitor TRU hours accurately.\n\n- Substitution and mitigation options: embodying Airbus production modification 30737 or the SB earlier removes the need to do the AD action later; operators may choose that route if it is operationally preferred.\n\n- Bureaucratic discretion and cross-reference: the AD relies on the CASA delegate’s regulatory power under subregulation 39.1(1) of CAR 1998 and cross‑references the DGAC (French authority) AD and the Airbus SB for technical method.\n\n**Concrete references within the instrument**\n\n- Applicability: identifies Airbus A319/A320/A321 and exclusions for aircraft with modification 30737 or SB A320-24-1099 embodied.\n- Requirement 1 and Requirement 2: the two operative instructions. Requirement 1 specifies replacement by SB A320-24-1099 Revision 1; Requirement 2 forbids future installation of the old part in position 2.\n- Compliance: timing is “either before 31 March 2004 or before 15,000 hours’ time in service, whichever occurs later” for the replacement; the installation prohibition takes effect after 31 March 2004.\n\n**Bottom line**\n\nThis AD mandates the replacement of a specific TRU part (Y005-2) in position 2 on certain A319/A320/A321 aeroplanes with an updated part (Y005-3), prohibits reinstalling the old part in that position after a set date, and ties the technical method to an Airbus Service Bulletin. Operators must schedule and pay for the work and monitor TRU hours to meet the compliance window. The stated purpose is to eliminate a failure mode that produced smoke smells in the cockpit."},"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-a320-145-transformer-rectifier-unit","history":"/api/acts/ad-a320-145-transformer-rectifier-unit/history","analysis":"/api/acts/ad-a320-145-transformer-rectifier-unit/analysis","conflicts":"/api/acts/ad-a320-145-transformer-rectifier-unit/conflicts","importantCases":"/api/acts/ad-a320-145-transformer-rectifier-unit/important-cases","documents":"/api/acts/ad-a320-145-transformer-rectifier-unit/documents"}}