{"id":"F2005L00094","name":"AD/A330/41 Amdt 1 - Passenger Gaseous Oxygen Containers Diaphragm","slug":"ad-a330-41-amdt-1-passenger-gaseous-oxygen-containers-diaphragm","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":33470,"registerId":"commonwealth-F2005L00094-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airbus Industrie A330 Series Aeroplanes","sectionType":"division","heading":"Airbus Industrie A330 Series Aeroplanes","content":"### Airbus Industrie A330 Series Aeroplanes\n\n| AD/A330/41 Amdt 1 | Passenger Gaseous OxygenContainers Diaphragm | 2/2005 |\n| ----------------- | -------------------------------------------- | ------ |\n\n| Applicability: | Model A330 aeroplanes, all serial numbers, on which Airbus modification 40257 has been embodied during production (installation of Passenger Gaseous Oxygen System) but on which Airbus modification 53578 was not embodied. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| | Note 1: Aircraft delivered after 11 September 2004, the effective date of DGAC Airworthiness Directive (AD) F-2004-152, are not affected by the requirements of this Directive. |\n| Requirement: | 1. The following dispatch limitations are mandatory for all flights: |\n| | - When dispatch is made with either one Cabin Pressure Controller (CPC) inoperative (MMEL item 21-31-01) or one air conditioning pack inoperative (MMEL 21-52-01), operators MUST ensure that from any point of the route, obstacle clearance is ensured to allow a rapid descent to FL 100.In that respect, following MMEL procedure must be added in the dispatch conditions for one CPC or one air conditioning pack inoperative:“... provided from any point of the route,obstacle clearance is ensured to allowa rapid descent to FL 100.”- When dispatch is made with one bleed air supply system inoperative (MMEL item 36-11-01), operators MUST ensure that from any point of the route, obstacle clearance is ensured to allow a rapid descent to FL 220 in case of remaining bleed failure. At FL 220, APU bleed air supply system is used for cabin pressurization.In that respect, following MMEL procedure must be added in the dispatch conditions for one bleed air supply inoperative:“... provided from any point of the route,obstacle clearance is ensured to allowa rapid descent to FL 220.” |\n\n| | Incorporation of MMEL TR N° 01-21/01Z ISSUE 01 and MMEL TR N° 01-36/01Z ISSUE 01 or a copy of this Directive in the aircraft operations manual is a satisfactory method of complying with this Requirement. |\n| --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| | 2. Identify the part number(s) (P/N) of the passenger gaseous oxygen container assemblies either installed on the aircraft or held as spares. For container assembly P/N(s) not listed in Airbus All Operator Telex (AOT) 35A3013 Revision 01, no further action is required by this Directive. |\n| | 3. For container assemblies with P/N(s) listed in AOT 35A3013 Revision 01, identify the manifold assembly P/N and serial number (S/N) in accordance with Dräger Aerospace Vendor Service Bulletin (VSB) XXG00-35-004 Revision 02. If both P/N and S/N of the manifold assembly are listed in VSB XXG00-35-004 Revision 02, apply the following corrective actions: |\n| | a. Replace the diaphragm installed in the manifold assembly in accordance with instructions given in VSB XXG00-35-004 Revision 02, and |\n| | b. If the container is installed on an aeroplane: |\n| | (i) Perform a leak check of the cabin emergency oxygen system in accordance with Aircraft Maintenance Manual (AMM) 35-23-00-790-801, and |\n| | (ii) Perform a system door release test in accordance with AMM 35-23-00-710-805. |\n| | 4. Identify the PN and SN of spare manifold assemblies in accordance with VSB XXG00-35-004 Revision 02. For each spare manifold assembly, if both P/N and S/N are listed in the VSB, replace the diaphragm installed in the manifold assembly in accordance with VSB XXG00-35-004 Revision 02. |\n| | If either the P/N or the S/N of the manifold assemblies is not listed in VSB XXG00-35-004 Revision 02, this Directive requires no further action. |\n| | Later versions of the following documents which are approved by the Direction Générale de l’Aviation Civile of France are acceptable for accomplishing the requirements of this Directive: |\n| | Airbus AOT35A3013 Revision 01 dated 26 August 2004MMEL TR N° 01-21/01Z ISSUE 01MMEL TR N° 01-36/01Z ISSUE 01 |\n| | Note 2: DGAC AD F-2004-152 R2 (EASA Approval 2004-11119) refers. |\n\n| Compliance: | For Requirement 1 - Remains unchanged as “As of the effective date of the original issue of this Directive’. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | For Requirements 2 and 3 - Remains unchanged as “Before 31 October 2004”. |\n| | For Requirement 4 - Remains unchanged as “Before installation on an aircraft but no later than 31 October 2004”. |\n| | This Amendment becomes effective on 17 February 2005. |\n| Background: | Qualification test and subsequent flow test, performed by the oxygen system supplier Dräger Aerospace, revealed that the oxygen flow of the passenger gaseous oxygen container assemblies may be degraded or blocked by sticking manifold diaphragm when used during a cabin decompression.During a slow depressurisation (loss of air conditioning packs or loss of the cabin pressure control system) and if the oxygen masks are triggered between flight level 150 and 250, the oxygen supply pressure will not be sufficient to free the diaphragm and oxygen will not flow to the passenger masks while deployed. |\n| | The original issue of this Directive required:- limitation of dispatch conditions by modifying the MMEL in case of one CPC or one air conditioning or one bleed air supply system inoperative,- an oxygen diaphragm replacement on the affected manifold assemblies, and- after replacement of the diaphragm on aircraft, a leak check of the cabin emergency oxygen system. |\n| | This Amendment does not require additional work but is issued to reduce the applicability by reference to Airbus modification 53578. |\n| | The original issue of this Airworthiness Directive became effective on 22 September 2004. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n13 December 2004\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 26 January 2005.","sortOrder":0},{"sectionNumber":"AD/A330/41 Amdt 1","sectionType":"part","heading":"AD/A330/41 Amdt 1","content":"## AD/A330/41 Amdt 1","sortOrder":1},{"sectionNumber":"Passenger Gaseous OxygenContainers Diaph","sectionType":"part","heading":"Passenger Gaseous OxygenContainers Diaphragm","content":"## Passenger Gaseous Oxygen \nContainers Diaphragm","sortOrder":2},{"sectionNumber":"2/2005","sectionType":"part","heading":"2/2005","content":"## 2/2005","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"This Amendment reduced the scope of the original Directive by excluding aircraft on which Airbus modification 53578 had been embodied. The Amendment states it \"does not require additional work but is issued to reduce the applicability by reference to Airbus modification 53578\" (Background). Other requirements (dispatch limitations, identification, diaphragm replacement, and post-replacement checks) remain unchanged."},"complexity_factors":["Conditional applicability depending on embodiment of Airbus modification 40257 and exclusion if modification 53578 embodied (Applicability; Background).","Multiple, interlinked operational and maintenance requirements (dispatch limitations + parts identification + parts replacement + functional checks) (Requirements 1–4).","Cross-references to several external documents: MMEL TRs, Airbus AOT 35A3013 Rev 01, Dräger VSB XXG00-35-004 Rev 02, AMM procedures, and DGAC/EASA ADs (Requirements; Acceptable documents; Note 2).","Conditional corrective action that applies only when both P/N and S/N match entries in the vendor service bulletin (Requirements 3 and 4).","Time-bound compliance windows differing by requirement (Requirement 1 effective date; Requirements 2–4 deadlines).","Operational impact clause requires route/altitude risk assessment from any point on the route (dispatch limitation language), which can be operationally complex to implement.","Use of different document types and versions (AOT, MMEL TR, VSB, AMM) with approval dependency on the DGAC increases interpretive steps.","Notes and exceptions (e.g. aircraft delivered after a certain date are excluded) create additional screening steps for operators."],"plain_english_summary":"**What this instrument does (mechanically)\n\n- Applicability: Applies to Airbus A330 aeroplanes that had Airbus modification 40257 (installation of the passenger gaseous oxygen system) fitted during production but did NOT have Airbus modification 53578 (see \"Applicability\" note). Aircraft delivered after 11 September 2004 are not affected (Note 1).**\n\n**Main mandatory actions (Requirements)**\n\n- Requirement 1 (Dispatch limitations): Operators must add dispatch conditions to cover continued safe descent and obstacle clearance when the airplane is dispatched with certain systems inoperative. Specifically:\n - If dispatched with one Cabin Pressure Controller (CPC) inoperative or one air conditioning pack inoperative (MMEL items cited), the operator must ensure that from any point on the planned route the aircraft can descend rapidly to flight level (FL) 100 while maintaining obstacle clearance. The MMEL procedure language quoted must be added to the dispatch conditions (Requirement 1).\n - If dispatched with one bleed air supply system inoperative (MMEL item cited), the operator must ensure that from any point on the planned route the aircraft can descend rapidly to FL 220 in the event of a further bleed failure; at FL 220 the APU bleed is used for cabin pressurisation. The quoted MMEL language must be added (Requirement 1).\n - Incorporating the specified MMEL Temporary Revisions (TRs) or a copy of this Directive into the Aircraft Operations Manual satisfies this requirement.\n\n- Requirements 2–4 (Parts identification and corrective work): Operators and maintainers must identify part numbers (P/N) and serial numbers (S/N) of installed and spare passenger gaseous oxygen container manifold assemblies and take corrective action only when both the manifold P/N and S/N match the manufacturer-issued list:\n - Requirement 2: Identify P/N(s) of the passenger gaseous oxygen container assemblies installed or held as spares; if a container P/N is not listed in Airbus AOT 35A3013 Revision 01, no further action is required for that container.\n - Requirement 3: For container P/Ns listed in Airbus AOT 35A3013 Rev 01, identify manifold assembly P/N and S/N per Dräger VSB XXG00-35-004 Rev 02. If both P/N and S/N appear in the VSB list, replace the diaphragm in the manifold assembly per VSB instructions. If the container is installed on the aircraft, after diaphragm replacement the operator must perform a cabin emergency oxygen system leak check (AMM ref) and a system door release test (AMM ref).\n - Requirement 4: For spare manifold assemblies identified per the VSB, if both P/N and S/N are listed in the VSB, replace the diaphragm before installation on an aircraft (and no later than the stated date in the Directive for installation).\n - If either P/N or S/N is not listed in the VSB, no action is required for that manifold assembly.\n\n- Acceptable compliance documents: Later versions of the listed Airbus and MMEL documents approved by the French aviation authority (DGAC) are acceptable for meeting the Directive.\n\n**Why the rule exists (as stated in the document)\n\n- Background: Qualification and flow tests by the oxygen system supplier (Dräger) found that the manifold diaphragm in certain passenger gaseous oxygen container assemblies can stick during some decompression scenarios. If masks deploy between FL150–FL250 during a slow depressurisation (for example when air conditioning packs or cabin pressure control are lost), the oxygen supply pressure may be insufficient to free the diaphragm and oxygen may not flow to passenger masks (Background).\n\n**Who is affected and who pays\n\n- Affected parties: Operators of Airbus A330 aeroplanes that have mod 40257 but not mod 53578, maintenance organisations (MROs) performing the inspections and diaphragm replacements, and holders of spare manifold assemblies for affected P/Ns/SNs (Applicability; Requirements 2–4).\n- Costs/who pays: Aircraft operators and their maintenance providers bear the costs of inspection, part identification, diaphragm replacement, and the post-maintenance leak and door-release tests. Incorporating MMEL TRs into operations manuals and any operational planning adjustments are also operator responsibilities (Requirement 1; Requirements 2–4).\n\n**How behaviour changes (practical effects)\n\n- Operators must add specific dispatch restrictions to ensure safe descent capability under specified single-failure conditions (Requirement 1). This can alter dispatch planning and route/altitude choices where the specified systems are inoperative.\n- Maintenance and inventory processes must include checks of part numbers and serial numbers against the manufacturer’s VSB and Airbus AOT, replacement of diaphragms where both P/N and S/N match the affected list, and performance of post-repair checks per the AMM (Requirements 2–4).\n\n**Trade-offs, implementation risks and compliance burdens (tested against the stated purpose)\n\n- Benefits stated: Targets a specific mechanical failure mode (sticking diaphragm) that can block oxygen flow to passenger masks in certain depressurisation scenarios (Background). The corrective action is targeted replacement of the diaphragm on listed manifold assemblies.\n- Direct costs and incentives: The costs (parts, labour, aircraft out-of-service time for replacement and testing, and administrative updates to manuals) fall on operators and MROs. Operators have an incentive to identify whether their fleet is within the affected subset (via P/N/S/N checks and modification 53578 status) to avoid unnecessary work.\n- Scope and substitution effects: The Directive limits corrective work to manifold assemblies where both P/N and S/N appear in the VSB list; assemblies not on the list require no action. The Amendment narrows scope by excluding aircraft with Airbus mod 53578 (see \"This Amendment does not require additional work but is issued to reduce the applicability by reference to Airbus modification 53578\"), so fewer aircraft are affected than under the original issue.\n- Implementation risk and compliance burden: Accurate record-keeping of P/Ns and S/Ns and access to the VSB/AOT are necessary. Mistakes in identification could lead to either unnecessary parts replacement or failure to address an affected part. Dispatch limitations increase operational complexity when flying with degraded systems.\n- Regulatory discretion and sourcing: The Directive requires use of a manufacturer/supplier service bulletin (Dräger VSB) for the corrective action and references Airbus AOT and MMEL TRs; operators therefore must follow manufacturer-prescribed procedures and rely on MRO capability to perform diaphragm replacement and the AMM checks.\n\n**Key deadlines and changes from the original Directive\n\n- Compliance timing in this instrument: Requirement 1 remained effective as of the original issue’s date; Requirements 2 and 3 were to be done before 31 October 2004; Requirement 4 before installation on an aircraft but no later than 31 October 2004 (Compliance). The Amendment itself did not add new work but reduced applicability by reference to modification 53578 (Background).\n\n(References: Applicability; Note 1; Requirements 1–4; Background; Compliance.)"},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This Amendment 1 explicitly narrows the scope compared to the original directive by excluding aircraft with Airbus modification 53578. The Background section confirms this is a reduction in applicability, not an expansion. The original safety intent (fixing stuck oxygen diaphragms) remains unchanged."},"complexity_factors":["Multiple nested conditional applicability tests (mod 40257 present AND mod 53578 absent)","Cross-references to four external technical documents (Airbus AOT, Dräger VSB, two MMEL Temporary Revisions)","Dual compliance pathways (incorporate MMEL TRs OR copy directive into operations manual)","Serial number-specific tracking requirements for both installed and spare parts","Four distinct requirements with different compliance dates and conditions","Technical aviation terminology requiring specialist knowledge (MMEL, CPC, FL 100/220, manifold assemblies)","Amendment structure that modifies original directive applicability rather than creating standalone requirements"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's aviation regulator (CASA) requiring specific fixes to aircraft.\n\n**What it does:**\nThis directive applies to **Airbus A330 aeroplanes** that have a particular passenger oxygen system installed (Airbus mod 40257) but lack a later safety modification (mod 53578). It addresses a dangerous fault where passenger oxygen masks might fail to deliver oxygen during a cabin decompression.\n\n**The safety problem:**\nDuring a slow loss of cabin pressure (between 15,000–25,000 feet), the diaphragm in the oxygen container can stick shut. If this happens, oxygen won't flow to passenger masks when they drop — potentially leaving passengers without breathable air during an emergency.\n\n**What airlines must do:**\n\n1. **Flight restrictions:** When flying with certain broken equipment (one cabin pressure controller, one air conditioning pack, or one bleed air system), airlines must ensure the flight path allows rapid descent to safe altitudes (10,000 or 22,000 feet respectively).\n\n2. **Check spare parts:** Identify which oxygen container part numbers are installed or held in stock.\n\n3. **Replace faulty diaphragms:** For affected containers, replace the sticking-prone diaphragm following the manufacturer's instructions, then perform leak checks and system tests.\n\n4. **Check spare manifold assemblies:** Replace diaphragms in spare parts inventory if they match the affected serial numbers.\n\n**Who it affects:**\nAirlines operating Airbus A330s with the specific oxygen system configuration, plus their maintenance crews and flight dispatchers.\n\n**Why it matters:**\nThis prevents a scenario where passengers put on oxygen masks during a decompression emergency but receive no oxygen due to a stuck valve — a potentially fatal failure in a real emergency."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a330-41-amdt-1-passenger-gaseous-oxygen-containers-diaphragm","history":"/api/acts/ad-a330-41-amdt-1-passenger-gaseous-oxygen-containers-diaphragm/history","analysis":"/api/acts/ad-a330-41-amdt-1-passenger-gaseous-oxygen-containers-diaphragm/analysis","conflicts":"/api/acts/ad-a330-41-amdt-1-passenger-gaseous-oxygen-containers-diaphragm/conflicts","importantCases":"/api/acts/ad-a330-41-amdt-1-passenger-gaseous-oxygen-containers-diaphragm/important-cases","documents":"/api/acts/ad-a330-41-amdt-1-passenger-gaseous-oxygen-containers-diaphragm/documents"}}