{"id":"F2005L03970","name":"AD/B737/239 Amdt 1 - Engine Fuel Feed System Electrical Bonding","slug":"ad-b737-239-amdt-1-engine-fuel-feed-system-electrical-bonding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":39855,"registerId":"commonwealth-F2005L03970-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 737 Series Aeroplanes","sectionType":"division","heading":"Boeing 737 Series Aeroplanes","content":"### Boeing 737 Series Aeroplanes\n\n| AD/B737/239 Amdt 1 | Engine Fuel Feed System Electrical Bonding | 1/2006 |\n| ------------------ | ------------------------------------------ | ------ |\n\n| Applicability: | Model 737-100, -200, -200C, -300, -400 and -500 series aeroplanes identified in Boeing Service Bulletin (SB) 737-28A1174, Revision 1, dated 18 July 2002.                                                                                                           |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Action in accordance with paragraph 3.B. of SB 737-28A1174, Revision 1.                                                                                                                                                                                          |\n|                | 2. Carry out any necessary corrective actions on deficiencies detected during the accomplishment of Requirement 1.                                                                                                                                                  |\n|                | Later revisions of the above SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2005-04-01, are considered acceptable for compliance with the equivalent Requirements of this Directive. |\n|                | Note 1: Operators may use their own CASA accepted equivalent procedures for draining the fuel tanks and gaining access to the fuel tanks.                                                                                                                           |\n|                | Note 2: The marking of the forward surface of the front spar in accordance with SB 737-28A1174, Revision 1, Figures 1 and 2, Step 18, is not required for compliance with this Directive.                                                                           |\n|                | Note 3: Actions accomplished before the effective date of this Directive in accordance with Boeing SB 737-28A1174 dated 20 December 2001 are acceptable for compliance with this Directive.                                                                         |\n|                | Note 4: FAA AD 2005-04-01 Amdt 39-13973 refers.                                                                                                                                                                                                                     |\n| Compliance:    | For Requirement 1 - Before 12 May 2010.                                                                                                                                                                                                                             |\n|                | For Requirement 2 - Before further flight after accomplishing Requirement 1.                                                                                                                                                                                        |\n|                | This Amendment becomes effective on 19 January 2006.                                                                                                                                                                                                                |\n\n| Background: | The FAA has determined that is necessary to reduce the potential for ignition sources inside fuel tanks. The original issue of this Directive was issued to prevent arcing or sparking at the interface between the bulkhead fittings of the engine fuel feed tube and the front spar inside the fuel tank of the wings and between the overwing fuel fill ports and the aeroplane structure during a lightning strike. Such arcing or sparking could provide a possible ignition source for the fuel vapour inside the fuel tank and cause consequent fuel tank explosions. |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This amendment whilst continuing the requirements of the original issue, allows compliance in accordance with later revisions of SB 737-28A1174 which have been approved by the FAA as an AMOC to the corresponding FAA airworthiness directive.                                                                                                                                                                                                                                                                                                                             |\n|             | The original issue of this Directive became effective on 12 May 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n30 November 2005","sortOrder":0},{"sectionNumber":"AD/B737/239 Amdt 1","sectionType":"part","heading":"AD/B737/239 Amdt 1","content":"## AD/B737/239 Amdt 1","sortOrder":1},{"sectionNumber":"Engine Fuel Feed System Electrical Bondi","sectionType":"part","heading":"Engine Fuel Feed System Electrical Bonding","content":"## Engine Fuel Feed System Electrical Bonding","sortOrder":2},{"sectionNumber":"1/2006","sectionType":"part","heading":"1/2006","content":"## 1/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original safety purpose (preventing fuel tank ignition sources) while expanding compliance flexibility. It allows operators to use later revisions of the Boeing service bulletin rather than being locked to Revision 1, provided those revisions are FAA-approved as Alternate Methods of Compliance. This is a procedural expansion, not a substantive change to the safety scope."},"complexity_factors":["Short, single-purpose directive (2 main requirements only)","Heavy reliance on external technical document (Boeing Service Bulletin 737-28A1174) - actual technical steps not reproduced in the legislation","4 explanatory notes providing exceptions and alternatives","Cross-reference to US FAA Airworthiness Directive 2005-04-01 for context","Conditional compliance paths (original SB, revised SB, or AMOC-approved alternatives)","No defined terms section - assumes technical aviation knowledge"],"plain_english_summary":"This mandatory airworthiness directive requires operators of certain Boeing 737-100 through -500 series to modify the engine fuel-feed electrical bonding per Boeing Service Bulletin 737-28A1174 (Rev 1) to prevent electrical arcing and possible fuel-tank ignition during lightning strikes. It affects airlines, maintenance engineers, and CASA oversight; compliance is mandatory by set deadlines, with repairs grounded until fixed. FAA-approved later revisions or some alternative procedures are permitted, and prior applicable work satisfies the requirement."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"The amendment preserves the original safety requirement but broadens acceptable means of compliance: later revisions of Boeing SB 737‑28A1174 that the FAA has approved as an Alternate Method of Compliance are explicitly acceptable. It also confirms acceptance of prior work done under the earlier SB and allows CASA‑accepted equivalent procedures for tank draining/access (Notes 1 and 3). The amendment does not expand the set of affected aircraft; it changes which compliance documents/methods are acceptable."},"complexity_factors":["Safety‑critical, technical work inside fuel tanks requiring tank draining and access (Note 1) — raises operational, tooling and competence requirements for operators.","Dependence on a specific Boeing Service Bulletin (SB 737‑28A1174 Rev 1) plus acceptance of later FAA‑approved revisions as Alternate Methods of Compliance — creates cross‑jurisdictional approval dependencies.","Applicability limited to particular 737 series and aircraft identified in the Service Bulletin — requires operators to verify applicability against SB serial/identification data.","\"Any necessary corrective actions\" is open‑ended and may vary scope and cost depending on defects found, increasing uncertainty and discretion for maintenance providers.","Two distinct timing constraints: Requirement 1 before 12 May 2010 and Requirement 2 before further flight after Requirement 1 — operational scheduling and possible aircraft downtime.","References to FAA AD 2005‑04‑01 and FAA AMOC process introduce regulatory interplay and reliance on FAA approvals for compliance choices.","Notes carve out conditional exceptions (e.g. marking not required, prior work accepted) which create recordkeeping and compliance evidence considerations.","Enforcement and acceptability include CASA discretion (acceptance of equivalent procedures) — administrative coordination between operator and regulator."],"plain_english_summary":"Requires operators of specified Boeing 737-100/200/300/400/500 series aeroplanes to carry out Boeing Service Bulletin 737‑28A1174 procedures to ensure electrical bonding at the engine fuel feed tube and overwing fill interfaces and to correct any defects. Later revisions of that Service Bulletin approved by the FAA as an Alternate Method of Compliance are acceptable. The stated objective is to reduce arcing inside fuel tanks (for example during lightning strikes) that could ignite fuel vapour. Operators meet inspection, tank-access and repair costs and compliance deadlines."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-239-amdt-1-engine-fuel-feed-system-electrical-bonding","history":"/api/acts/ad-b737-239-amdt-1-engine-fuel-feed-system-electrical-bonding/history","analysis":"/api/acts/ad-b737-239-amdt-1-engine-fuel-feed-system-electrical-bonding/analysis","conflicts":"/api/acts/ad-b737-239-amdt-1-engine-fuel-feed-system-electrical-bonding/conflicts","importantCases":"/api/acts/ad-b737-239-amdt-1-engine-fuel-feed-system-electrical-bonding/important-cases","documents":"/api/acts/ad-b737-239-amdt-1-engine-fuel-feed-system-electrical-bonding/documents"}}