{"id":"F2005L01333","name":"AD/A320/176 - Centre Fuel Tank Bonding","slug":"ad-a320-176-centre-fuel-tank-bonding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":35098,"registerId":"commonwealth-F2005L01333-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airbus Industrie A319, A320 and A321 Ser","sectionType":"division","heading":"Airbus Industrie A319, A320 and A321 Series Aeroplanes","content":"### Airbus Industrie A319, A320 and A321 Series Aeroplanes\n\n| AD/A320/176 | Centre Fuel Tank Bonding | 7/2005 |\n| ----------- | ------------------------ | ------ |\n\n| Applicability: | Airbus A320 and A321 series aeroplanes, all serial numbers, except aeroplanes that had Airbus modification 23645 incorporated during production or either Airbus Service Bulletin A320-28-1055 original issue dated 12 July 1993 or Revision 1 dated 8 March 1994 embodied whilst in service. |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Install a bonding lead between the low pressure valve and the adjacent pipe assembly in accordance with SB A320-28-1055 Revision 1 or later revision approved by the French Direction General de l’Aviation Civile (DGAC).                                                                    |\n|                | Note: DGAC AD F-2005-058 (EASA Approval 2005-3065) refers.                                                                                                                                                                                                                                    |\n| Compliance:    | Before 31 December 2009.                                                                                                                                                                                                                                                                      |\n|                | This Airworthiness Directive becomes effective on 7 July 2005.                                                                                                                                                                                                                                |\n| Background:    | Following the TWA800 in flight incident the United States Federal Aviation Administration issued Special Federal Aviation Regulation (SFAR) 88. The European Joint Aviation Authorities adopted similar regulations to SFAR 88 requiring a design review against fuel tank explosion risks.   |\n|                | This Directive mandates the installation of additional electrical bonding between the low pressure valve and the adjacent pipe assembly and is a consequence of this design review.                                                                                                           |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n19 May 2005","sortOrder":0},{"sectionNumber":"AD/A320/176","sectionType":"part","heading":"AD/A320/176","content":"## AD/A320/176","sortOrder":1},{"sectionNumber":"Centre Fuel Tank Bonding","sectionType":"part","heading":"Centre Fuel Tank Bonding","content":"## Centre Fuel Tank Bonding","sortOrder":2},{"sectionNumber":"7/2005","sectionType":"part","heading":"7/2005","content":"## 7/2005","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive stays within the original safety-focused purpose: it implements a targeted retrofit to reduce fuel-tank ignition risk identified by post-TWA800 design reviews (SFAR 88–style work). It does not broaden the scope beyond that mitigation (no additional systems, operational restrictions, recurring charges, or widening of affected aircraft types beyond the stated A320/A321 applicability). The directive’s exemptions (airframes already modified in production or already embodying the SB) are typical narrow carve-outs and do not constitute a scope expansion."},"complexity_factors":["Single technical requirement (install a bonding lead) with a single specified Service Bulletin.","Narrow applicability with two explicit exemptions (production modification 23645 or prior embodiment of SB A320-28-1055 original/Rev 1).","One compliance deadline and one effective date (clear timing, no rolling or conditional deadlines).","Cross-reference to an external authority for approval of later SB revisions (DGAC), creating a single external dependency.","Reference to related regulatory instruments (SFAR 88 and DGAC AD) for background only; no layered conditional logic or nested exceptions."],"plain_english_summary":"**What this directive does (mechanically)\n\n- Requires that operators of Airbus A320 and A321 aeroplanes install a small electrical bonding lead (a short wire that equalises electrical potential to prevent sparks) between the centre fuel tank low-pressure valve and the adjacent fuel pipe assembly.  The installation must follow Airbus Service Bulletin A320-28-1055 Revision 1 (or a later revision approved by the French DGAC).  (Source: Requirement.)\n\n- Applies to all Airbus A320 and A321 series aircraft unless the aeroplane already had Airbus production modification 23645 fitted, or Service Bulletin A320-28-1055 (original or Revision 1) was already embodied in service. (Source: Applicability.)\n\n- The directive came into force on 7 July 2005 and required compliance by 31 December 2009. (Source: Compliance.)\n\nWhy it was made (official rationale)\n\n- The action follows the post‑TWA800 regulatory work (SFAR 88 in the US and similar European reviews) that required design reviews of fuel tanks to reduce the risk of ignition/explosion. The directive implements one of the resulting modifications: additional electrical bonding to reduce the chance of an electrical spark in the centre fuel tank. (Source: Background.)\n\nWho it affects and who pays\n\n- Primary duty-holders: aircraft operators/owners and the maintenance organisations they contract. Those parties must arrange and pay for the parts, labour and aircraft downtime necessary to retrofit the bonding lead, unless the aircraft already meets the applicability exemptions. (Source: Applicability; Requirement.)\n\nWho decides and what discretion exists\n\n- The directive requires work to be done in accordance with a specified Airbus Service Bulletin. Later revisions of that Service Bulletin are acceptable only if approved by the French Direction Générale de l'Aviation Civile (DGAC). That approval process is the primary regulatory discretion point. (Source: Requirement.)\n\nPractical effects and implementation considerations\n\n- Technical action: physical retrofit of an electrical bonding lead at a specific place in the centre fuel tank plumbing.\n- Operational impact: aircraft out of service for the work; parts and qualified maintenance labour required; the operator must track compliance status for each affected airframe. (Source: Requirement; Compliance.)\n- Compliance verification: maintenance records and release-to-service entries will show embodiment of the Service Bulletin and any DGAC approvals for later revisions.\n\nCosts, incentives and trade-offs (tested against the directive’s purpose)\n\n- Direct cost: purchase of the bonding lead kit (parts) and labour time to perform the retrofit. These are concentrated and one-off per aeroplane. (Source: Requirement.)\n- Opportunity cost: aircraft downtime for modification consumes maintenance hangar time and may displace other scheduled work. (Source: Compliance timing.)\n- Incentives: operators have a clear compliance deadline, creating a scheduling incentive to perform the work before the stipulated date; operators who already fitted the SB or the production mod are exempt, creating a grandfathering benefit for those aircraft. (Source: Applicability; Compliance.)\n- Implementation risk: incorrect installation or paperwork errors could leave an aeroplane non-compliant; work must be done to the approved Service Bulletin standard by qualified personnel. (Source: Requirement.)\n\nEffects on private enterprise and markets\n\n- Competition and prices: the directive imposes a compliance cost shared by all affected operators; smaller operators may feel the per-aircraft administrative and cash-flow burden more acutely than large carriers, but the technical nature of the work does not preferentially advantage particular operators. (Source: Applicability; Requirement.)\n- Productivity and operations: short-term loss of aircraft availability for modification; no ongoing operational constraint once embodied. (Source: Compliance.)\n- Ownership and contract freedom: owners remain free to decide how and when to perform the work subject to the compliance deadline; they may subcontract the work to third-party maintenance providers. (Source: Requirement; Compliance.)\n\nConcentrated benefits vs diffuse costs\n\n- The principal benefit—reduced risk of fuel-tank ignition—is concentrated on occupants and operators of the modified aeroplanes (and regulators seeking harmonised mitigation). The cost is concentrated on the same operators (parts, labour, downtime). The directive does not create ongoing fees or market-entry barriers beyond the one-off retrofit obligation. (Source: Background; Requirement.)\n\nNet description (mechanical summary followed by purpose-claim)\n\n- Mechanically: retrofit a bonding lead between the centre fuel tank low-pressure valve and adjacent pipe per Airbus SB A320-28-1055 Rev 1 (or later DGAC-approved revision) for all A320/A321s unless already modified. (Requirement; Applicability.)\n- Purpose-claim: the change implements a design-review mitigation coming out of post-TWA800 regulations (SFAR 88–type work) to reduce the risk of fuel-tank ignition. (Background.)"},"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":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — a specific safety modification to address fuel tank explosion risks identified post-TWA800. The applicability exclusions (for aircraft already modified) are standard aviation safety practice and do not represent scope creep."},"complexity_factors":["Single, specific technical requirement (install one bonding lead)","Only 2 exemption categories (factory modification or prior service bulletin embodiment)","No nested conditional logic or cross-references to other legislation","Clear compliance deadline (single date)","Short document (approximately 200 words of substantive content)","Only one defined technical reference (SB A320-28-1055) with clear revision hierarchy"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:**\nOrders owners and operators of certain Airbus A320 and A321 passenger jets to install an extra electrical bonding (grounding) wire between the low pressure fuel valve and the nearby pipe in the centre fuel tank. This prevents dangerous static electricity buildup that could spark and cause a fuel tank explosion.\n\n**Who it affects:**\n- All Airbus A320 and A321 aircraft, regardless of serial number\n- **Except** planes that already had a specific factory modification (mod 23645) installed during manufacturing, OR\n- **Except** planes that already had the repair done using Airbus Service Bulletin A320-28-1055 (original July 1993 version or Revision 1 from March 1994)\n\n**Why it matters:**\nThis rule was created in response to the **TWA Flight 800 disaster** — a 1996 explosion of a Boeing 747 near New York that killed 230 people, caused by a fuel tank explosion. The US and European regulators required all aircraft manufacturers to review their fuel tank designs for explosion risks. This AD implements one of those safety fixes for Airbus planes.\n\n**Key deadlines:**\n- The rule took effect on **7 July 2005**\n- Aircraft owners had until **31 December 2009** to complete the modification\n\n**What owners must do:**\nInstall the bonding lead following the exact instructions in Airbus Service Bulletin A320-28-1055 Revision 1 (or a later version approved by French aviation authorities)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-176-centre-fuel-tank-bonding","history":"/api/acts/ad-a320-176-centre-fuel-tank-bonding/history","analysis":"/api/acts/ad-a320-176-centre-fuel-tank-bonding/analysis","conflicts":"/api/acts/ad-a320-176-centre-fuel-tank-bonding/conflicts","importantCases":"/api/acts/ad-a320-176-centre-fuel-tank-bonding/important-cases","documents":"/api/acts/ad-a320-176-centre-fuel-tank-bonding/documents"}}