{"id":"F2006B01919","name":"AD/A320/28 - Pylon Fuel Return Line Connection and Pylon Sealant Integrity","slug":"ad-a320-28-pylon-fuel-return-line-connection-and-pylon-sealant-integrity","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41141,"registerId":"commonwealth-F2006B01919-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A320/28 - Pylon Fuel Return Line Connection and Pylon Sealant Integrity","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nAirbus Industrie A319, A320 and A321 Series Aeroplanes\n\nAD/A320/28 Pylon Fuel Return Line Connection\n\nand Pylon Sealant Integrity\n\n  \n2/93\n\nDM\n\nApplicability: Serial numbers 002 to 180, 183 to 194, 196 to 315, 317 to 321, 323 to 325 and 328 to\n\n334 inclusive.\n\nRequirement: Action in accordance with Airbus Industrie AOT 28-04 Revision 1 dated 9 September 1992.\n\nNote: DGAC AD 92-228-037(B) of 28 October 1992 refers.\n\nCompliance: Within 500 flying hours from 1 Jan 1993.\n\nBackground: During the final phase of a landing, the Number 2 engine fire warning of an aircraft illuminated twice for several seconds. The engine was shut down normally. A small fire fed by hot fuel from a loose return line connection had occurred on top of the engine. This fuel had passed through deteriorated sealant in the pylon drain system on to the engine where it ignited.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD applies to the specific serial numbers listed and requires actions set out in Airbus Industrie AOT 28-04 Revision 1 to be completed within the stated 500 flying-hour period. The source text contains no indication that the AD’s scope was altered from any prior intent; it sets a clear, limited scope defined by the applicability list and the referenced AOT. (Applicability; Requirement; Compliance)"},"complexity_factors":["Narrow technical scope: targets a specific component and failure mode (pylon fuel return line connection and pylon drain sealant). (Requirement; Background)","External dependency: compliance requires following an external manufacturer document (Airbus Industrie AOT 28-04 Rev 1) rather than containing full procedures in the AD. (Requirement)","Serial-number specificity: only aircraft with the listed serial numbers are affected, requiring operators to check applicability. (Applicability)","Fixed compliance window: a single, short compliance interval (500 flying hours from 1 Jan 1993) creates scheduling pressure. (Compliance)","Regulatory formality: issued as an airworthiness directive under Part 39, creating a legal compliance obligation rather than guidance. (header)"],"plain_english_summary":"What this directive does (mechanically)\n\n- The Civil Aviation Safety Authority published an airworthiness directive that requires specific Airbus A319/A320/A321 aeroplanes (listed by serial number) to have their pylon fuel return line connection and pylon sealant inspected and/or corrected in accordance with a manufacturer technical instruction: Airbus Industrie AOT 28-04 Revision 1 dated 9 September 1992. (Requirement)\n- Operators of the affected aeroplanes must complete that work within 500 flying hours from 1 January 1993. (Compliance)\n\nWho is affected\n\n- Only Airbus A319/A320/A321 aeroplanes with the serial numbers listed in the AD are covered. The applicability list appears at the start of the AD. (Applicability)\n- The operators or owners of those aeroplanes are the parties that must arrange and pay for the inspections and any rectification work required by the Airbus AOT. (Applicability; Requirement)\n\nWhy the rule was issued (official rationale and mechanical effect)\n\n- The AD was issued after an incident in which, during the final phase of landing, an engine fire warning illuminated because hot fuel leaked from a loose return line connection and passed through deteriorated pylon drain sealant onto the engine, where it ignited. The background given in the AD describes that sequence. (Background)\n- The mechanical effect of the AD is to require inspection and corrective action at the pylon fuel return line connection and the pylon drain sealant so the same fuel leakage path is addressed. Compliance is achieved by following the specified Airbus Industrie AOT. (Requirement)\n\nPractical consequences, incentives and trade-offs\n\n- Who pays: The direct cost is borne by owners/operators of the listed serial-number aircraft because they must carry out the Airbus AOT work. (Applicability; Requirement)\n- Timing and operational impact: Work must be done within a fixed operational window (500 flying hours from 1 Jan 1993), which creates a scheduling and potential aircraft downtime obligation for operators. (Compliance)\n- Method and choice constraints: The AD requires action “in accordance with” the manufacturer’s AOT, so the technical method and scope of inspection/repair are set by that document rather than by each operator. That channels how maintenance resources are used. (Requirement)\n- Safety vs. opportunity cost: The AD targets a specific failure mode (fuel feed through deteriorated sealant leading to engine fire). Addressing it consumes maintenance resources and aircraft availability that could otherwise be used for other tasks; the AD’s background ties the required action to preventing that fuel-leak/fire sequence. (Background; Requirement)\n- Implementation risk and compliance burden: Effective mitigation depends on correct application of the Airbus AOT and timely completion. The AD sets the regulatory requirement; operators must ensure the AOT work is performed to meet that requirement. (Requirement; Compliance)\n\nAdministrative and legal framing\n\n- The AD is presented under the Civil Aviation Regulations framework (PART 39 — Schedule of Airworthiness Directives), so it is a regulatory obligation rather than a voluntary manufacturer advisory. (header)\n- The AD refers operators to the Airbus AOT for the technical steps to be followed rather than reproducing those steps in the AD text. (Requirement)\n\nConcise summary\n\n- This AD requires certain A319/A320/A321 aircraft (specific serial numbers) to undergo inspection and corrective work on the pylon fuel return line connection and pylon drain sealant according to Airbus Industrie AOT 28-04 Rev 1, to be completed within 500 flying hours from 1 January 1993. The AD was issued in response to an in-service event where a loose return line connection and deteriorated sealant allowed fuel to reach and ignite on an engine. (Applicability; Requirement; Compliance; Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of preventing engine fires caused by fuel line and sealant failures in the pylon area."},"complexity_factors":["Very short document (approximately 200 words)","Only 4 defined elements: applicability (serial number ranges), requirement (reference to external Airbus document), compliance deadline, and background","Single condition: compliance tied to flying hours accumulated after a fixed date","No nested exceptions or conditional logic — straightforward mandate","Heavy reliance on external technical document (Airbus AOT 28-04) for actual procedural details, which keeps the legislative text simple but pushes complexity to the referenced standard"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) to fix a dangerous defect in certain Airbus aircraft.\n\n**What it does:**\nOrders airlines and aircraft operators to inspect and repair the fuel return line connections and sealant in the engine pylons (the structures that attach engines to the wings) of specific Airbus A319, A320, and A321 planes.\n\n**Why it matters:**\nA loose fuel return line combined with deteriorated sealant caused a small engine fire during landing on one aircraft. Hot fuel leaked through the damaged sealant, dripped onto the engine, and ignited. This directive prevents similar fires by forcing operators to follow Airbus's specific repair instructions.\n\n**Who it affects:**\n- **Aircraft:** Airbus A319, A320, and A321 planes with specific serial numbers (roughly early production models, serial numbers 002–334 with some gaps)\n- **Operators:** Airlines and owners of these specific aircraft must comply\n\n**What must be done:**\nOperators must follow **Airbus Industrie Alert Operators Transmission (AOT) 28-04 Revision 1** — a technical bulletin from Airbus describing the inspection and repair procedure. This must be completed within **500 flying hours** starting from 1 January 1993.\n\n**Key point:** This is not optional. Airworthiness Directives are legally binding safety requirements. Failure to comply means the aircraft cannot legally fly."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-28-pylon-fuel-return-line-connection-and-pylon-sealant-integrity","history":"/api/acts/ad-a320-28-pylon-fuel-return-line-connection-and-pylon-sealant-integrity/history","analysis":"/api/acts/ad-a320-28-pylon-fuel-return-line-connection-and-pylon-sealant-integrity/analysis","conflicts":"/api/acts/ad-a320-28-pylon-fuel-return-line-connection-and-pylon-sealant-integrity/conflicts","importantCases":"/api/acts/ad-a320-28-pylon-fuel-return-line-connection-and-pylon-sealant-integrity/important-cases","documents":"/api/acts/ad-a320-28-pylon-fuel-return-line-connection-and-pylon-sealant-integrity/documents"}}