{"id":"F2006B01903","name":"AD/A320/161 - Fuel System - Air Release Valve (ARV)","slug":"ad-a320-161-fuel-system-air-release-valve-arv","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41112,"registerId":"commonwealth-F2006B01903-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 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\nAirbus Industrie A319, A320 and A321 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/A320/161 Fuel System - Air Release Va","sectionType":"part","heading":"AD/A320/161 Fuel System - Air Release Valve (ARV) 10/2004","content":"# AD/A320/161 Fuel System \\- Air Release Valve (ARV) 10/2004\n\nApplicability: AIRBUS A319, A320 and A321 aircraft that are equipped with Air Release Valve (ARV) FR-HITEMP Part Number (PN) 9813365, 9813395 or 9813445.\n\nAircraft on which no replacement of the ARV has been performed since embodiment of AIRBUS modification 26102 in production or AIRBUS Service Bulletin (SB) A320-28-1123 in service are not affected by the requirements of this Directive.\n\nNote 1: FR-HITEMP was previously known as “FLIGHT REFUELLING”.\n\nRequirement: Modify the ARV PN 9813365, 9813395 or 9813445 in accordance with the instructions given in AIRBUS SB A320-28-1123 or later revisions approved by the French DGAC.\n\nNote 2: For modification of the ARV PN 9813365, compliance with SB A320-28- 1002 is required.\n\nNote 3: DGAC AD F-2004-120 (EASA approval No 2004-7519) refers.\n\nCompliance: Before 30 June 2007.\n\nThis Airworthiness Directive becomes effective on 30 September 2004.\n\nBackground: One operator has reported an engine shut down in fuel gravity mode. Analysis has shown that the float of the ARV PN 9813365, 9813395 or 9813445 absorbs fuel and will no longer float, and consequently will fail to function as required. In the case where the engines are in gravity mode, there could be enough air ingested through the ARV to allow the engine to shut down. This Directive mandates the requirement to replace the ARV with one that incorporates an improved type of float.\n\n![](image.002.jpeg)  \n\nGary J Carr\n\n![](image.001.png)Delegate of the Civil Aviation Safety Authority 19 August 2004","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD stays within the original safety purpose: it addresses a specific failure mode of certain ARV part numbers that could allow air ingestion and engine shutdown in gravity fuel mode. The AD prescribes a targeted corrective action (modify or replace the ARV with an improved float) and excludes aircraft that already incorporate the corrective modification. There is no material broadening of scope beyond correcting that identified unsafe condition."},"complexity_factors":["Narrow applicability: only Airbus A319/A320/A321 aircraft fitted with FR‑HITEMP ARV PNs 9813365, 9813395 or 9813445 are affected","Single, specific mandated action: modify the ARV per Airbus SB A320‑28‑1123 (plus SB A320‑28‑1002 for PN 9813365)","One fixed compliance deadline (30 June 2007)","Cross‑references to two Airbus Service Bulletins and a foreign authority (French DGAC/EASA) for approved revisions","A single exception clause for aircraft that already embody Airbus mod 26102 or SB A320‑28‑1123","Short document with no layered conditional logic or multiple alternative compliance pathways"],"plain_english_summary":"**What this directive does (mechanically)**\n\n- This is an Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) that requires specific Airbus A319, A320 and A321 aeroplanes to have their Air Release Valve (ARV) modified. (See \"Applicability\" and \"Requirement\".)\n- The AD applies only to aircraft fitted with FR‑HITEMP ARV part numbers 9813365, 9813395 or 9813445. Aircraft that already received Airbus modification 26102 in production or the Airbus Service Bulletin (SB) A320‑28‑1123 in service are excluded (they do not have to comply) (\"Applicability\").\n- The required action is to modify the ARV in accordance with Airbus SB A320‑28‑1123 (or later revisions approved by the French DGAC). For PN 9813365, compliance with SB A320‑28‑1002 is also required (\"Requirement\", Notes 2 and 3).\n- The deadline for completing the modification is 30 June 2007 (\"Compliance\").\n\n**Who this affects (who pays and who acts)**\n\n- Aircraft operators/owners of Airbus A319, A320 or A321 fitted with the specified ARV part numbers must arrange and pay for the modification. Maintenance organisations or licensed engineers will perform the work following the referenced Airbus service bulletins.\n- CASA (through its delegate) is the regulatory authority that mandated the action; the AD requires operators to follow the stated SB instructions (\"Requirement\").\n\n**Why it matters (the stated safety reason and how the rule addresses it)**\n\n- Background provided by CASA: one operator reported an engine shutdown when the engine was operating in fuel gravity feed mode. Investigation indicated the float inside the listed ARV part numbers can absorb fuel, sink, and stop functioning as intended; this can allow air to enter the fuel feed and cause an engine to shut down. The AD requires replacement/modification of the ARV to a version that uses an improved float to prevent this failure mode (\"Background\").\n\n**Practical mechanics and compliance details**\n\n- Operators must follow the instructions in Airbus SB A320‑28‑1123 (or later DGAC‑approved revisions). For PN 9813365, SB A320‑28‑1002 also must be used (Notes 2 and 3).\n- Aircraft that already embody Airbus mod 26102 in production or SB A320‑28‑1123 in service are already compliant and do not need further action (Applicability).\n- The AD references the corresponding French DGAC AD (F‑2004‑120 / EASA approval No 2004‑7519) as the approving authority for the SBs (Note 3).\n\n**Costs, incentives, trade‑offs and implementation risks**\n\n- Costs and who bears them: operators bear direct costs — parts, labour and aircraft downtime for the modification. The AD creates a near‑term spike in demand for the improved ARV parts or modification kits from the manufacturer or approved suppliers.\n- Incentives and scheduling: operators have an incentive to combine this work with other scheduled maintenance to minimise downtime and cost. Those who already implemented the referenced modification are exempt, so past investment reduces future cost exposure (Applicability).\n- Compliance burden and bureaucracy: the AD requires adherence to specific Airbus SB procedures and DGAC‑approved revisions; maintenance organisations must follow those technical instructions exactly to be compliant. CASA's role is prescriptive rather than discretionary once the AD is issued.\n- Market effects: suppliers of the improved ARV or modification services receive concentrated demand; independent MROs (maintenance, repair and overhaul providers) can compete to supply the parts and do the work so long as they comply with the SBs and regulatory approvals.\n- Implementation risk: incorrect modification or use of non‑approved parts/technique risks non‑compliance and could leave the unsafe condition uncorrected. Operators must confirm the relevant SB revision is DGAC‑approved per the AD.\n- Opportunity costs: scheduled maintenance capacity may be strained near the compliance deadline, potentially increasing short‑term maintenance lead times and costs.\n\n**Source claims and testing them**\n\n- The AD states the safety problem is a float that absorbs fuel and then fails to float, allowing air ingestion and possible engine shutdown (Background). That claim is the reason CASA mandated the modification; the AD achieves the stated aim by requiring an improved float design (Requirement). The main trade‑off is the cost, downtime and logistics burden on operators versus the safety benefit of reducing the risk of engine shutdown in gravity feed mode.\n\n(Referenced sections: Applicability; Requirement; Compliance; Background; Notes 1–3.)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It addresses a specific unsafe condition identified in a particular valve model on specific Airbus aircraft types. The directive has not expanded beyond its original safety purpose of mandating valve replacement to prevent engine shutdown."},"complexity_factors":["Short, single-purpose directive (approximately 300 words)","Only 3 specific part numbers affected, with clear applicability criteria","Simple conditional logic: one exemption clause for aircraft already modified","Single cross-reference to French DGAC/EASA approval for traceability","One nested requirement (Note 2 adds additional compliance for one specific part number)","No defined terms section - technical terms explained in context or via notes"],"plain_english_summary":"This CASA safety order requires operators of Airbus A319/A320/A321 fitted with FR‑HITEMP Air Release Valves (parts 9813365, 9813395, 9813445) to modify or replace the ARV per Airbus Service Bulletins (with an extra SB for part 9813365) to prevent float saturation that can admit air in gravity mode and cause engine shutdown.  \n\nExempt are aircraft already modified under Airbus mod 26102 or SB A320‑28‑1123. Action was required before 30 June 2007; the order took effect 30 Sep 2004."},"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-a320-161-fuel-system-air-release-valve-arv","history":"/api/acts/ad-a320-161-fuel-system-air-release-valve-arv/history","analysis":"/api/acts/ad-a320-161-fuel-system-air-release-valve-arv/analysis","conflicts":"/api/acts/ad-a320-161-fuel-system-air-release-valve-arv/conflicts","importantCases":"/api/acts/ad-a320-161-fuel-system-air-release-valve-arv/important-cases","documents":"/api/acts/ad-a320-161-fuel-system-air-release-valve-arv/documents"}}