{"id":"F2008L00697","name":"AD/J4100/25 - Fuel Tank Bonding Leads and Fuel Pipe Clearances","slug":"ad-j4100-25-fuel-tank-bonding-leads-and-fuel-pipe-clearances","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":72738,"registerId":"commonwealth-F2008L00697-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"BAe Systems (Operations) Jetstream 4100 ","sectionType":"division","heading":"BAe Systems (Operations) Jetstream 4100 Series Aeroplanes","content":"### BAe Systems (Operations) Jetstream 4100 Series Aeroplanes\n\n| AD/J4100/25 | Fuel Tank Bonding Leads andFuel Pipe Clearances | 5/2008 DM |\n| ----------- | ----------------------------------------------- | --------- |\n\n| Applicability: | Jetstream 4100 series aeroplanes, all models, all serial numbers.                                                                                                                                                                                          |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Inspect the bonding leads between ribs 1 and 9, and between ribs 16 and 19, in the left (LH) and right (RH) wings in accordance with paragraph 2B(2) of BAE Systems (Operations) Ltd Service Bulletin (SB) J41-28-013 Revision 1 dated 10 January 2008. |\n|                | 2. If, as a result of the Requirement 1 inspection, any defective bonding leads are found, replace the bonding leads with airworthy parts.                                                                                                                 |\n|                | 3. Examine all fuel system pipe runs inside the LH and RH wings in accordance with paragraph 2B(3) of SB J41-28-013 Revision 1.                                                                                                                            |\n|                | 4. If, as a result of the Requirement 3 examination, incorrect clearances are found, adjust the clearances to meet the requirements of the SB.                                                                                                             |\n|                | 5. Install additional electrical bonding of components within the LH and RH wings in accordance with paragraphs 2B(4) to 2B(15) of SB J41-28-013 Revision 1.                                                                                               |\n|                | Later revisions of SB J41-28-013, approved by the European Aviation Safety Agency (EASA), are acceptable for compliance with the Requirements of this Directive.                                                                                           |\n|                | Note: EASA AD 2008-0040 refers.                                                                                                                                                                                                                            |\n| Compliance:    | For Requirements 1, 3 and 5 - At the next major inspection or wing tank access, or within 24 months after the effective date of this Directive, whichever occurs first.                                                                                    |\n|                | For Requirements 2 and 4 - Before the next flight after the applicable inspection/examination.                                                                                                                                                             |\n|                | This Airworthiness Directive becomes effective on 14 March 2008.                                                                                                                                                                                           |\n\n| Background: | Following the assessment of fuel tank wiring installations required by SFAR 88 and equivalent JAA/EASA policy, BAE Systems identified two features in the Jetstream 4100 where the need for design changes was apparent. One of these is addressed by SB J41-28-013 which introduces additional bonding leads between pipes, structure and various components to improve the electrical bond paths within the fuel tank areas. This design change is identified by modification number JM41659. Additionally, SB J41-28-013 provides instructions to inspect the existing bonding leads, to replace any defective leads and to examine all fuel system pipe runs in the wings to ensure appropriate clearances are maintained.Insufficient or defective bonding in the fuel tank area, if not corrected, could lead to ignition of fuel vapours and subsequent fuel tank explosion.For the reason stated above, this Directive requires the installation of additional bonding leads, inspection of existing bonding leads and all fuel system pipe runs in the wings together with follow-on corrective actions, as necessary. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n5 March 2008","sortOrder":0},{"sectionNumber":"AD/J4100/25","sectionType":"part","heading":"AD/J4100/25","content":"## AD/J4100/25","sortOrder":1},{"sectionNumber":"Fuel Tank Bonding Leads andFuel Pipe Cle","sectionType":"part","heading":"Fuel Tank Bonding Leads andFuel Pipe Clearances","content":"## Fuel Tank Bonding Leads and  \nFuel Pipe Clearances","sortOrder":2},{"sectionNumber":"5/2008 DM","sectionType":"part","heading":"5/2008 DM","content":"## 5/2008 DM","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive implements the design changes and inspections identified in the SFAR 88/EASA assessment for Jetstream 4100 fuel‑tank areas. It is limited to bonding leads and fuel‑pipe clearances on the specified aeroplanes and accepts later EASA‑approved revisions of the referenced service bulletin; it does not broaden applicability beyond the stated aircraft type or introduce additional unrelated obligations."},"complexity_factors":["Technical tasks: electrical bonding installation, inspection, and fuel-pipe clearance adjustments require qualified maintenance personnel.","Reference to an external Service Bulletin (SB J41-28-013) and acceptance of later EASA‑approved revisions creates dependence on external technical documentation.","Multiple discrete requirements with differing compliance timelines (immediate corrective action before next flight; inspections within 24 months or at next major inspection).","Requirement to replace parts with airworthy parts introduces procurement and certification steps.","Applicability to all serial numbers of the Jetstream 4100 increases the universe of affected operators.","Safety‑critical context (SFAR 88 assessment) raises regulatory scrutiny and lower tolerance for non‑compliance."],"plain_english_summary":"This directive requires inspection, replacement where defective, and addition of electrical bonding leads and adjustment of fuel-pipe clearances in the left and right wings of all BAe Jetstream 4100 aeroplanes, following BAE Systems Service Bulletin J41-28-013 (or later EASA-approved revisions). It affects aircraft operators and maintenance organisations: inspections must occur at the next major inspection/wing-tank access or within 24 months, defects corrected before the next flight, to reduce the stated risk of fuel‑vapour ignition in wing tanks."},"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":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It addresses a specific safety issue identified through the SFAR 88 fuel tank system safety assessment process — namely, electrical bonding deficiencies in Jetstream 4100 wing fuel tanks. The directive has not expanded beyond this original technical safety purpose."},"complexity_factors":["Short, single-purpose directive with only 5 numbered requirements","Minimal defined terms (only standard aviation acronyms like LH/RH, SB, EASA)","Clear compliance timeline with simple conditional logic ('whichever occurs first')","Single cross-reference to an external technical document (Service Bulletin J41-28-013) rather than complex legislative cross-referencing","No nested exceptions or conditional sub-clauses within requirements","Straightforward cause-and-effect structure (inspect → if found defective → replace)"],"plain_english_summary":"This CASA Airworthiness Directive requires owners and operators of BAe Jetstream 4100 series aircraft to inspect and remediate electrical bonding and fuel‑tank fuel‑pipe clearances in the wing tanks, and install additional bonding where needed.  \n\nIt affects all Jetstream 4100s in Australia and matters because inadequate bonding can allow sparks in fuel vapour—raising the risk of fuel‑tank explosion. Work must be done at the next major inspection/wing‑tank access or within 24 months."}},"importantCases":[],"_links":{"self":"/api/acts/ad-j4100-25-fuel-tank-bonding-leads-and-fuel-pipe-clearances","history":"/api/acts/ad-j4100-25-fuel-tank-bonding-leads-and-fuel-pipe-clearances/history","analysis":"/api/acts/ad-j4100-25-fuel-tank-bonding-leads-and-fuel-pipe-clearances/analysis","conflicts":"/api/acts/ad-j4100-25-fuel-tank-bonding-leads-and-fuel-pipe-clearances/conflicts","importantCases":"/api/acts/ad-j4100-25-fuel-tank-bonding-leads-and-fuel-pipe-clearances/important-cases","documents":"/api/acts/ad-j4100-25-fuel-tank-bonding-leads-and-fuel-pipe-clearances/documents"}}