{"id":"F2007L01050","name":"AD/B717/20 - Electrical Bonding","slug":"ad-b717-20-electrical-bonding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":64991,"registerId":"commonwealth-F2007L01050-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 717 Series Aeroplanes","sectionType":"division","heading":"Boeing 717 Series Aeroplanes","content":"### Boeing 717 Series Aeroplanes\n\n| AD/B717/20 | Electrical Bonding | 5/2007 |\n| ---------- | ------------------ | ------ |\n\n| Applicability: | Model 717-200 airplanes, as identified in Boeing Service Bulletin (SB) 717-28-0011, Revision 2, dated 19 July 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Replace attaching hardware of the bulkhead nipple assemblies of the left and right wing vent boxes with new electrical bonding attaching hardware, carry out resistance testing of the new electrical bonds and fuel leakage testing of the reworked nipple assemblies. All actions are to be carried out in accordance with the Accomplishment Instructions of Boeing SB 717-28-0011, Revision 2.                                                                                                                                                                                                         |\n|                | Note 1: Note (e) of Figure 1 of the service bulletin refers to a class `L' resistance test. However, Section 20-50-01 of the Boeing Standard Wiring Practices Manual (SWPM) no longer refers to class `L.' The class `L' resistance test was related to lightning protection and specified a maximum resistance of 0.0025 ohm, this appeared in earlier versions of the SWPM. The term \"class `L' \" is not important in this context and the directions of note (e) of Figure 1 of the service bulletin are otherwise acceptable as written (ie the resistance must not exceed 2.5 milliohm [0.0025 ohm]). |\n|                | Actions accomplished before the effective date of this Directive in accordance with Boeing SB 717-28-0011, dated 16 April 2004, or Revision 1, dated 24 January 2006; are acceptable for compliance with the corresponding actions specified in this Directive.                                                                                                                                                                                                                                                                                                                                            |\n|                | Later revisions of the SB 717-28-0011, Revision 2, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-05-06, are considered acceptable for compliance with the equivalent Requirements of this Directive.                                                                                                                                                                                                                                                                                                                      |\n|                | Note 2: FAA AD 2007-05-06 Amdt 39-14967 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| Compliance:    | Within 78 months after the effective date of this Directive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n|                | This Airworthiness Directive becomes effective on 10 May 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n\n| Background: | This Directive requires replacing certain attaching hardware of the bulkhead nipple assemblies of the left and right wing vent boxes with new electrical bonding attaching hardware, together with accomplishing resistance testing of the new electrical bonds, and fuel leakage testing of the reworked nipple assemblies. The Directive results from fuel system reviews conducted by the manufacturer. |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | The Directive is issued to ensure a conductive path is provided, from the bulkhead nipple assemblies of the left and right wing vent boxes to the airframe structure inside the wing fuel tanks, to dissipate high-amperage lightning-induced currents, which might otherwise create an ignition source for fuel vapours inside the wing vent boxes and lead to an explosion of the fuel tanks.            |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n16 March 2007","sortOrder":0},{"sectionNumber":"AD/B717/20","sectionType":"part","heading":"AD/B717/20","content":"## AD/B717/20","sortOrder":1},{"sectionNumber":"Electrical Bonding","sectionType":"part","heading":"Electrical Bonding","content":"## Electrical Bonding","sortOrder":2},{"sectionNumber":"5/2007","sectionType":"part","heading":"5/2007","content":"## 5/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive stays within its original safety-focused purpose: to ensure an adequate electrical bonding path on specified Boeing 717-200 wing vent box bulkhead nipple assemblies to mitigate lightning-induced ignition risk. It does not broaden into unrelated regulatory areas. The Directive accepts prior compliant work under earlier service bulletin versions and later FAA-approved SB revisions as AMOCs, which adds procedural flexibility but does not expand substantive scope beyond the original technical remedy."},"complexity_factors":["Narrow applicability: only Boeing 717-200 airplanes identified in Boeing SB 717-28-0011 Rev 2","Reliance on external documents: the substantive work and tests are specified in Boeing SB 717-28-0011 (and references to Boeing SWPM) rather than fully spelled out in the Directive","Numeric technical threshold: a single precise resistance limit (≤ 2.5 milliohm)","Conditional compliance credits: accepts earlier SB versions (two specific versions) as compliant","AMOC cross-reference: accepts later SB revisions approved by the FAA as Alternate Methods of Compliance (ties to FAA AD 2007-05-06)","Limited procedural complexity: two required tests (electrical resistance and fuel leakage) and a single replacement action","Time-bound compliance: one fixed compliance window (78 months)"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires owners/operators of Boeing 717-200 aeroplanes (those specifically identified in Boeing Service Bulletin (SB) 717-28-0011, Revision 2) to replace the attaching hardware for the bulkhead nipple assemblies of the left and right wing vent boxes with new electrical-bonding attaching hardware.\n- After replacement, the new electrical bonds must be tested for electrical resistance and the modified nipple assemblies must be tested for fuel leakage.\n- The work must be carried out exactly as described in the “Accomplishment Instructions” of Boeing SB 717-28-0011, Revision 2.\n- The specific resistance requirement is that the bond resistance must not exceed 2.5 milliohm (0.0025 ohm). (A note explains this corresponds to the older SWPM “class L” lightning-protection test.)\n- Compliance time: within 78 months of the Directive’s effective date.\n- Credit: if the modification and tests were already done before the effective date in accordance with earlier versions of the Boeing service bulletin (dated 16 April 2004 or Revision 1 dated 24 January 2006), those earlier actions are accepted as compliant.\n- Flexibility: later revisions of the Boeing SB that the US FAA approves as an Alternate Method of Compliance (AMOC) to FAA AD 2007-05-06 are also acceptable for compliance with this Directive.\n\n**Who is affected**\n\n- Aircraft owners and operators of Boeing 717-200 aeroplanes identified in the referenced Boeing SB.\n- Maintenance organisations and technicians who perform the replacement and the electrical and fuel-leakage tests.\n- Regulators (the Civil Aviation Safety Authority via the Directive) in that they set the requirement and accept certain AMOCs.\n\n**Why it matters (stated purpose and mechanical effect)**\n\n- The manufacturer and regulator say the change ensures a conductive path from the bulkhead nipple assemblies of the wing vent boxes to the airframe inside the wing fuel tanks so that high-amperage lightning-induced currents can be dissipated safely. The stated risk being addressed is that without an adequate conductive path a lightning current could create an ignition source for fuel vapours inside the vent boxes and lead to a fuel-tank explosion.\n\n**Practical consequences, costs and implementation considerations**\n\n- Who pays: operators/owners pay for new parts, labour, test equipment or contracted maintenance, and for aircraft downtime while the work is done.\n- Behaviour change required: scheduling the aircraft into maintenance, sourcing the specified bonding hardware, performing low-resistance (milliohm) electrical testing and fuel-leakage testing per the Boeing instructions, and documenting compliance.\n- Compliance burden: operators must obtain and follow the Boeing SB work instructions, ensure test equipment can accurately measure very low resistances (milliohm range), and carry out fuel leakage tests that require access to the vent box/nipple assemblies.\n- Implementation risks and constraints: availability of the correct parts, availability of suitably qualified maintenance personnel, calibration and capability of low-resistance test instruments, and aircraft downtime (which has direct commercial cost). Fuel leakage testing requires safe handling procedures and may increase inspection complexity and time.\n- Regulatory flexibility: the Directive accepts prior compliant work (credit for earlier SB versions) and permits later FAA-approved SB revisions as acceptable AMOCs; that reduces the need for bespoke approvals and supports use of FAA-reviewed changes.\n\n**Market and enterprise effects (light, practical lens)**\n\n- Competition: the requirement does not alter market structure or ownership; it does create demand for the specified bonding hardware and for maintenance/inspection services — a concentrated demand among 717-200 operators.\n- Prices/productivity: operators will face one-time and possibly recurring maintenance costs and aircraft downtime, which can affect operating costs and utilisation. Independent maintenance providers can perform the work if they follow the SB and hold the necessary approvals, so the rule does not prohibit independent contractors from competing to supply the service.\n- Contract freedom and discretion: operators retain discretion about when (within the 78-month window) to schedule the work, subject to airworthiness requirements and fleet operational constraints. The regulator’s acceptance of FAA-approved AMOCs reduces the need for additional approvals.\n\n**Source claims vs trade-offs**\n\n- The instrument’s stated safety purpose (dissipate lightning currents to avoid ignition) is explicit in the Directive. The trade-offs are concrete: increased maintenance cost, need for specific testing capability, and aircraft downtime versus reduced lightning-related ignition risk. The Directive narrows the technical solution (hardware replacement plus tests) and ties compliance to Boeing SB instructions and FAA AMOCs, which centralises the technical procedure with the manufacturer and the FAA."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific safety-critical maintenance issue (lightning protection in fuel systems). It has not expanded beyond its original technical scope; it precisely targets the identified ignition source risk in Boeing 717 wing vent boxes without additional regulatory baggage."},"complexity_factors":["Single discrete technical requirement with clear mechanical actions (hardware replacement + two tests)","Only 1 defined technical reference (Boeing SB 717-28-0011, Revision 2) with explicit acceptance of earlier/later revisions","One compliance deadline (78 months from effective date) with no conditional triggers or phased implementation","Contains one clarifying note about obsolete terminology ('class L' resistance test) that simplifies rather than complicates understanding","Cross-references to FAA AD 2007-05-06 for alternative compliance methods but this is optional, not mandatory navigation","Narrow applicability (single aircraft model, specific part numbers identified in external document)"],"plain_english_summary":"This AD requires operators of Boeing 717-200s covered by Boeing Service Bulletin 717-28-0011, Rev 2 to replace the bolts/fasteners attaching bulkhead nipple assemblies in left and right wing vent boxes with electrical-bonding hardware so lightning currents can safely dissipate instead of arcing in fuel tanks. It also requires conductivity and fuel-leak checks and allows previous or later approved SBs as compliance; work had to be completed within 78 months of 10 May 2007."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b717-20-electrical-bonding","history":"/api/acts/ad-b717-20-electrical-bonding/history","analysis":"/api/acts/ad-b717-20-electrical-bonding/analysis","conflicts":"/api/acts/ad-b717-20-electrical-bonding/conflicts","importantCases":"/api/acts/ad-b717-20-electrical-bonding/important-cases","documents":"/api/acts/ad-b717-20-electrical-bonding/documents"}}