{"id":"F2006B01869","name":"AD/A320/122 Amdt 1 - Crew Oxygen Supply","slug":"ad-a320-122-amdt-1-crew-oxygen-supply","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41065,"registerId":"commonwealth-F2006B01869-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A320/122 Amdt 1 - Crew Oxygen Supply","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/A320/122 and issues the following 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\n![](image.001.png)\n\nAirbus Industrie A319, A320 and A321 Series Aeroplanes\n\nAD/A320/122\n\nAmdt 1\n\n  \nCrew Oxygen Supply 10/2001\n\nApplicability: All A319, A320 or A321 series aeroplanes, without either Airbus Industrie Modification 21946 or 21999 embodied during production or Airbus Industrie Service Bulletin (SB) A320-35-1003 dated 26 August 1991 or Revision 1 dated 28 January 1993 incorporated whilst in service.\n\nRequirement: Replace the low pressure oxygen valve Part Number (P/N) DVE90-04 by a new modified valve P/N DVE90-05 or DVE90-06 in accordance with SB A320-35-1003, A320-35-1003 Revision 1 and/or SB A320-35-1016 dated 31 July 1996.\n\nNote: DGAC AD 2001-237(B) R1 refers.\n\nCompliance: Before 31 October 2002.\n\nThis Amendment becomes effective on 4 October 2001.\n\nBackground: The Direction Générale de L’Aviation Civile of France has advised that, following an inflight test, crew oxygen was not available. Investigation revealed that there was a discrepancy between the position of the solenoid operated low-pressure valve and the controlling push button switch. Several reset actions of the push button were required before oxygen became available. This condition could, in the event of rapid decompression or smoke in the cockpit, prevent the crew correctly responding to an emergency.\n\nThis original issue of this Directive required the replacement of the solenoid operated oxygen low pressure valve.\n\nThis Amendment identifies an additional modification that, if embodied during production, nullifies the requirement to replace the solenoid operated oxygen low pressure valve\n\nAirbus Industrie A319, A320 and A321 Series Aeroplanes\n\nAD/A320/122 Amdt 1 (Continued)\n\nThe original issue of this directive became effective 6 September 2001.\n\n![](image.002.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 13 August 2001\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 12 September 2001.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"This amendment narrowed the population of aircraft that must undergo the valve replacement by adding an explicit exemption: aircraft that already had certain production modifications (Mod 21946 or 21999) embodied, or that had SB A320-35-1003 (or Revision 1) incorporated while in service, do not need the replacement (Applicability). The original AD required replacement for the subject fleet; the amendment recognises additional pre‑existing modifications as providing equivalent mitigation, thereby reducing the number of aircraft required to carry out the mandated work."},"complexity_factors":["Single, focused safety action (valve replacement) rather than multiple interdependent measures","One primary conditional exemption (aircraft with Mod 21946 or 21999 embodied during production, or SB A320-35-1003/Revision 1 incorporated in service)","Cross‑references to 2 Airbus Service Bulletins (A320-35-1003 and A320-35-1016) and a DGAC AD (external documents required to implement the work)","Clear, single compliance deadline (31 October 2002)","Short background explanation but no nested exceptions or lengthy defined‑term section"],"plain_english_summary":"**What this directive does (mechanics):**\n\n- Requires certain Airbus A319/A320/A321 aeroplanes to have the crew low‑pressure oxygen valve replaced. Specifically, the old solenoid operated valve P/N DVE90-04 must be replaced with the modified valve P/N DVE90-05 or P/N DVE90-06.\n- The valve replacement must be carried out following the instructions in Airbus Service Bulletins A320-35-1003 (or Revision 1) and/or A320-35-1016 (\"Requirement\").\n- Aircraft that already have Airbus production Mod 21946 or Mod 21999 embodied, or that already have SB A320-35-1003 (or its Revision 1) incorporated in service, are excluded from this replacement requirement (\"Applicability\").\n- The replacement must be completed by 31 October 2002 (\"Compliance\"); the amendment took effect on 4 October 2001.\n\n**Who is affected:**\n\n- Operators and owners of Airbus A319, A320 and A321 aircraft that do not already have the listed production modifications (21946 or 21999) or the specified Service Bulletin actions incorporated. Mechanical workshops (MROs) and parts suppliers will also be involved because they perform the replacement and supply the new valve.\n\n**Why it matters (safety rationale and source claim):**\n\n- The Direction Générale de l’Aviation Civile (DGAC) reported an inflight test in which crew oxygen did not become available immediately because the solenoid operated low‑pressure valve and the push‑button controlling it were out of sync. Several push‑button resets were needed before oxygen flowed (\"Background\").\n- The AD states that this discrepancy can prevent crews from getting oxygen during an emergency such as rapid decompression or cockpit smoke, so the mechanical fix (valve replacement) is mandated to correct that unsafe condition.\n\n**Practical effects, incentives and costs (analyst notes):**\n\n- Who pays: aircraft operators bear the direct costs — purchase of the replacement valve(s), labour to install them, and aircraft downtime while the work is performed (Requirement; Compliance).\n- What operators can choose to do: operators can either show that one of the exempting modifications or SBs has already been embodied (in which case no replacement is required), or they must schedule and carry out the valve replacement per the Airbus SB instructions.\n- Implementation risk and compliance burden: the technical work must follow the Airbus SB procedures; incorrect installation or failure to document compliance risks regulatory non‑compliance and continued safety exposure (Requirement).\n- Trade‑offs and opportunity cost: spending maintenance time and money on the valve replacement displaces other maintenance work or operational use of the aircraft during the required downtime. Operators may coordinate the replacement with other scheduled maintenance to reduce disruption.\n- Concentrated benefits, diffuse costs: the safety benefit (avoiding crew oxygen unavailability) accrues directly to flight crews and passengers in the unlikely event of an emergency; the costs are concentrated on the operators who must pay for the parts and labour.\n- Administrative path: CASA issued this AD under its regulatory power (subregulation 39.1(1) of CAR 1998) and references the DGAC notice and Airbus SBs as the technical instructions for compliance (Applicability; Note).\n\n**What changed in the amendment:**\n\n- The amendment identifies an additional production modification (or SB incorporation) that, if already present on an aeroplane, removes the need to replace the valve. In short, the amendment narrows the set of aircraft required to do the replacement by recognising certain existing modifications as an alternative mitigation (Amendment; Applicability).\n\n(Sections cited: Applicability; Requirement; Compliance; Background; Note/Amendment.)"},"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 amendment maintains the original scope of the directive. It adds an exemption for aircraft that already have certain factory modifications installed, but this is a narrowing refinement rather than scope creep. The core purpose — ensuring crew oxygen system reliability — remains unchanged."},"complexity_factors":["Single, specific technical requirement (valve replacement)","Limited applicability (three specific Airbus models)","Clear exemption criteria (two production modifications or specific service bulletins)","Single compliance deadline with no conditional timing","No nested definitions or extensive cross-referencing to other legislation","Background section provides straightforward safety rationale"],"plain_english_summary":"This CASA Airworthiness Directive requires operators of certain Airbus A319/A320/A321 aircraft to replace a cockpit oxygen valve (P/N DVE90-04) that can fail to supply emergency oxygen to the crew. Aircraft with the specified factory modifications or service bulletin are exempt. It affects operators without those mods and must be completed before 31 October 2002 — critical because valve failure could prevent pilots receiving oxygen in sudden depressurisation or smoke emergencies."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-122-amdt-1-crew-oxygen-supply","history":"/api/acts/ad-a320-122-amdt-1-crew-oxygen-supply/history","analysis":"/api/acts/ad-a320-122-amdt-1-crew-oxygen-supply/analysis","conflicts":"/api/acts/ad-a320-122-amdt-1-crew-oxygen-supply/conflicts","importantCases":"/api/acts/ad-a320-122-amdt-1-crew-oxygen-supply/important-cases","documents":"/api/acts/ad-a320-122-amdt-1-crew-oxygen-supply/documents"}}