{"id":"F2006B01855","name":"AD/A320/106 Amdt 3 - Fuel Tank Electrical Bonding","slug":"ad-a320-106-amdt-3-fuel-tank-electrical-bonding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41051,"registerId":"commonwealth-F2006B01855-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A320/106 Amdt 3 - Fuel Tank Electrical Bonding","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/A320/106 Amdt 2 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/A320/106\n\nAmdt 3\n\n  \nFuel Tank Electrical Bonding 7/2002\n\nApplicability: Model A319, A320 and A321 series aeroplanes, all serial numbers, which do not have Airbus Modification 27150 and 27955 incorporated during production or Airbus Industrie Service Bulletin (SB) A320-28-1077 Revision 4 embodied.\n\nModel A321-211 and A321-231 series aeroplanes, serial numbers (MSN) 633, 663, 666, 668, 677, 680, 687, 715, 725, 775, 781, 808, 815, 823, 841 and 852 without\n\nAirbus Modification 27472 incorporated during production or Airbus Industrie SB A320-28-1079 embodied.\n\nRequirement: 1. Model A319, A320 and A321 series aeroplanes \\- Improve the electrical bonding by reworking the bonding bolts and installing additional electrical bonding leads within the fuel tanks in accordance with SB A320-28-1077 Revision 4.\n\nAccomplishment of SB A320-28-1077 Revisions 1, 2 or 3 is considered an acceptable means of compliance provided that the additionally works required by SB A320-28-1077 Revision 4 at rib 15 is completed.\n\n2. Model A321-211 and A321-231 series aeroplanes \\- Modify the bonding in the additional centre fuel tank (ACT) in accordance with SB A320-28-1079.\n\nNote: DGAC France AD 2002-202(B) refers.\n\nCompliance: Remains unchanged as ‘Before 31 December 2004’. This Amendment becomes effective on 11 July 2002.\n\nBackground: During a scheduled inspection of an Airbus Industrie A300 fuel tank, evidence of a possible electrical discharge was found. Whilst it has not been possible to confirm that an electrical discharge occurred, the cause may have been the degradation of the electrical bonding leads within the fuel tanks. The degradation included corrosion, rupture and bad electrical contact. The fuel tanks on Airbus Industrie A319, A320 and A321 aeroplanes are of the same design as the fuel tanks on the A300 and are therefore subject to the same risk of an internal electrical discharge occurring.\n\nAirbus Industrie A319, A320 and A321 Series Aeroplanes\n\nAD/A320/106 Amdt 3 (Continued)\n\nThe original issue of this Directive required the introduction of modified electrical bonding within the fuel tanks, to alleviate the risk of electrical discharges occurring.\n\nAmendment 1 clarified the requirement by ensuring the rework of the bonding bolts was also addressed.\n\nAmendment 2 required the completion of additional work for those aircraft incorporating SB A320-28-1077 at the original issue.\n\nThis Amendment clarified the extra work required by Amendment 2 and introduced additional requirements (modification of bonding in ACT fuel tanks) for certain A321-211 and A321-231 aeroplanes.\n\nThe original issue of this Airworthiness Directive became effective on 23 March 2000.\n\nAmendment 1 became effective on 19 April 2001.\n\nAmendment 2 became effective on 21 March 2002.\n\n![](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 31 May 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 19 June 2002.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original 2000 directive addressed electrical bonding in fuel tanks for the main A320 family fleet. Through three amendments, the scope has expanded to: (1) clarify bolt rework requirements (Amendment 1), (2) address partial compliance scenarios from earlier service bulletins (Amendment 2), and (3) add an entirely new aircraft subset (specific A321-211/231 models with Additional Centre Tanks) with distinct modification requirements (Amendment 3). The directive now governs two distinct technical modifications across multiple applicability categories rather than the single original requirement."},"complexity_factors":["Multiple amendment layers requiring cross-referencing to understand current state (original issue plus Amendments 1, 2, and 3)","Two distinct applicability groups with different technical requirements (main fleet vs specific A321-211/231 serial numbers)","Conditional compliance pathway: earlier Service Bulletin revisions accepted only if supplemented with specific additional work at 'rib 15'","Reference to external technical documents (Airbus Service Bulletins A320-28-1077 Rev 4 and A320-28-1079) that are not reproduced in the directive","Specific serial number enumeration for the A321-211/231 subset (17 individual MSN numbers listed)","Cross-reference to French aviation authority directive (DGAC France AD 2002-202(B)) without explanation of its relevance"],"plain_english_summary":"This CASA Airworthiness Directive orders Airbus A319/A320/A321 operators to improve electrical bonding inside fuel tanks to prevent sparks from degraded bonding leads, after evidence of possible electrical discharge in an A300 tank. It also requires specific A321-211/231 serial-numbered aircraft to modify Additional Centre Tanks. This third amendment clarifies required extra work for earlier partial fixes and adds the ACT requirement. All corrective work must be done before 31 December 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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This Amendment (Amdt 3) expands and clarifies the original directive’s scope. Compared with the original AD, Amendment 3: (a) clarifies the extra work required at rib 15 for aircraft that complied with earlier revisions of SB A320-28-1077; and (b) adds a new, explicit requirement to modify electrical bonding in the additional centre tank (ACT) for certain A321-211 and A321-231 serial numbers (unless a specific production modification or SB has already been embodied). Those additions increase the number of specific work items and the subset of aircraft covered by mandatory modification, so the instrument’s scope has grown beyond its original, more general rework requirement."},"complexity_factors":["Cross-reference to multiple Airbus Service Bulletins (SB A320-28-1077 Revision 4 and earlier revisions; SB A320-28-1079)","Conditional acceptability of earlier SB revisions only if additional rib 15 work is done","Exemptions linked to specific Airbus production modifications (Mods 27150, 27955, 27472)","Specific serial-number list for A321-211 and A321-231 variants (granular applicability)","Revocation of a prior amendment and incorporation of changes from earlier amendments (history and layering of requirements)","Single compliance deadline (clear) but work involves confined-space fuel-tank maintenance that raises procedural complexity","Note referring to a foreign authority AD (DGAC France) — implicit cross-jurisdictional alignment"],"plain_english_summary":"**What this instrument does, in plain terms**\n\n- This is an Airworthiness Directive (AD) that cancels the previous amendment (Amdt 2) and replaces it with Amendment 3 for AD/A320/106. An AD is a legally binding safety requirement issued by the aviation regulator that aircraft owners/operators must follow.\n\n- Mechanically, the AD requires operators of certain Airbus A319, A320 and A321 aeroplanes to improve the electrical bonding inside the fuel tanks. Concretely, that means:\n  - For A319, A320 and most A321 aeroplanes: rework the bonding bolts and install additional electrical bonding leads inside the fuel tanks by following Airbus Service Bulletin (SB) A320-28-1077 Revision 4. Earlier revisions (1–3) are acceptable only if the additional rib 15 work required by Revision 4 is also done.\n  - For specific A321-211 and A321-231 serial numbers listed in the AD: modify the bonding in the additional centre tank (ACT) per SB A320-28-1079 unless Airbus Modification 27472 or that SB has already been embodied.\n\n- Planes that had certain factory modifications already fitted (Airbus Mods 27150 or 27955, or certain SBs embodied) are excluded from some of the requirements; the AD specifies those exemptions in the applicability section.\n\n- The compliance timing stated in this amendment remains: the work must be done before 31 December 2004. The AD became effective on 11 July 2002.\n\n**Why the regulator required this**\n\n- The regulator’s stated reason: during an inspection of an A300 fuel tank, inspectors found signs that suggested a possible electrical discharge (they could not fully confirm it). The suspected cause was degraded electrical bonding leads in the fuel tank — corrosion, broken leads or poor electrical contact. Because A319/A320/A321 tanks use the same design, CASA concluded they face the same hazard and mandated the bonding upgrade to reduce the risk of an internal electrical discharge.\n\n**Who it affects and who pays**\n\n- Primary duty-bearers: aircraft owners/operators of the affected A319/A320/A321 aeroplanes and the certificated maintenance organisations that carry out the work. The operator is legally responsible for compliance.\n- Financial cost: operators pay for inspection/maintenance time, labour, parts and aircraft downtime required to carry out the SB work or embodied modifications.\n\n**How compliance works in practice**\n\n- The operator arranges for maintenance to be performed in accordance with the specified Airbus Service Bulletins. If the airplane already has the stated Airbus production modifications or the SB already embodied, that airplane may be out of scope or have reduced work.\n- Maintenance organisations must follow the SB instructions and record completion in the aircraft maintenance records to demonstrate compliance with the AD.\n\n**Practical trade-offs, risks and implementation considerations (tested against the regulator’s stated purpose)**\n\n- Cost vs risk reduction: the AD imposes a direct cost (labour, parts, downtime) on operators in return for a reduction in the risk of electrical discharge inside fuel tanks.\n- Concentration of burden and benefit: costs are borne by individual operators (diffuse), while the safety benefit is distributed across all users of the type. Operators with aircraft that already have the stated production modifications avoid the cost.\n- Implementation risk and complexity: the work requires access inside fuel tanks and compliance with fuel-tank safety procedures (heightened safety precautions), specialised maintenance capability, and potential scheduling impacts — all of which raise implementation complexity and cost.\n- Compliance discretion: CASA (via the delegate) prescribes the required actions and references Airbus Service Bulletins as the standard of compliance. Operators may need regulatory approval if they seek an alternative means of compliance.\n- Behavioural effect: operators will schedule and budget for the mandated work; some may accelerate other scheduled maintenance to combine tasks and reduce downtime.\n\n**Where the AD points to for detailed instructions**\n\n- The AD mandates work “in accordance with” Airbus SB A320-28-1077 Revision 4 (and accepts earlier revisions only with the rib‑15 work done) and SB A320-28-1079 for the ACT on certain A321s. The SBs contain the technical steps, parts, and detailed work standards."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-106-amdt-3-fuel-tank-electrical-bonding","history":"/api/acts/ad-a320-106-amdt-3-fuel-tank-electrical-bonding/history","analysis":"/api/acts/ad-a320-106-amdt-3-fuel-tank-electrical-bonding/analysis","conflicts":"/api/acts/ad-a320-106-amdt-3-fuel-tank-electrical-bonding/conflicts","importantCases":"/api/acts/ad-a320-106-amdt-3-fuel-tank-electrical-bonding/important-cases","documents":"/api/acts/ad-a320-106-amdt-3-fuel-tank-electrical-bonding/documents"}}