{"id":"F2011L01846","name":"AD/B737/347 Amdt 1 - Centre Wing Tank Autoshutoff Wiring","slug":"ad-b737-347-amdt-1-centre-wing-tank-autoshutoff-wiring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":87145,"registerId":"commonwealth-F2011L01846-current","compilationNumber":null,"startDate":"2026-04-02","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/B737/347 Amdt 1 | Centre Wing Tank Autoshutoff Wiring | 18/2011 |\n| ------------------ | ----------------------------------- | ------- |\n\n| Applicability: | Model 737-600, -700, -700C, -800 and -900 series aeroplanes, on which Boeing Alert Service Bulletin (ASB) 737-28A1206 dated 11 January 2006 has been accomplished. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | Perform the actions as detailed in FAA Emergency AD 2008-24-51. |\n| Compliance: | Date remains unchanged to that detailed in the original issue of this directive.Despite the new AD/B737/347 Amdt 1, an exclusion or an alternate method of compliance that was in force before the coming into effect of AD/B737/347 Amdt 1 continues to be in force. |\n| | This Amendment becomes effective on 30 September 2011. |\n| Background: | The United State’s Federal Aviation Administration (FAA) received a report of failure of the left-hand fuel pump of the CWT to shut off after being selected “OFF” by the flightcrew during flight on a Boeing Model 737-700 aeroplane. Subsequent to that report, the failure was found on two additional aeroplanes. Information indicates that the autoshutoff system appears to function normally; however, when the flightcrew manually turns off the CWT pump switches, that action turns off the right-hand pump, but re-energizes the left-hand pump due to incorrect wiring. The low-pressure lights turn off, incorrectly indicating to the flightcrew that power to both pumps has been removed. The failure condition results in continual running of the left-hand fuel pump without indication to the flightcrew, which could lead to localized overheating of parts inside the fuel pump, and which could produce an ignition source inside the fuel tank. |\n| | Investigation revealed that incorrect wiring could occur on airplanes on which an autoshutoff system was installed in accordance with Boeing ASB 737-28A1206. Functional tests conducted in accordance with that service bulletin are not adequate to detect the incorrect wiring condition.This Directive is issued to prevent extended dry-running of the fuel pump, which could lead to localized overheating of parts inside the fuel pump, and which could produce an ignition source inside the fuel tank. |\n\n| | This amendment deletes the original text of the AD and incorporates the original FAA AD by reference. This was done to facilitate easier cross referencing to FAA AD 2011-18-03 Amdt 39-16785 which details the terminating actions for the requirements of this AD.The original issue of this AD became effective on 20 November 2008.Alternative methods of compliance for AD 2008-24-51 that are approved by the FAA are acceptable as a means of compliance against this AD. |\n| --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)\n\nMike Higgins \nDelegate of the Civil Aviation Safety Authority\n\n5 September 2011","sortOrder":0},{"sectionNumber":"AD/B737/347 Amdt 1","sectionType":"part","heading":"AD/B737/347 Amdt 1","content":"## AD/B737/347 Amdt 1","sortOrder":1},{"sectionNumber":"Centre Wing Tank Autoshutoff Wiring","sectionType":"part","heading":"Centre Wing Tank Autoshutoff Wiring","content":"## Centre Wing Tank Autoshutoff Wiring","sortOrder":2},{"sectionNumber":"18/2011","sectionType":"part","heading":"18/2011","content":"## 18/2011","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment did not materially expand the subject matter or the population covered. It replaces the original Australian AD text with a version that incorporates the FAA Emergency AD by reference to simplify cross-referencing, and it explicitly preserves previously approved alternate methods of compliance. The core safety objective — correct incorrect CWT autoshutoff wiring on aeroplanes modified per Boeing ASB 737‑28A1206 — remains unchanged."},"complexity_factors":["Short, single-subject directive focused on wiring of CWT autoshutoff","Limited applicability (only certain 737 models with Boeing ASB 737-28A1206 embodied)","Incorporates an external FAA Emergency AD (2008-24-51) by reference rather than reproducing detailed steps","Cross-reference to a later FAA AD (2011-18-03) for terminating actions","Allows pre-existing approved alternate methods of compliance (AMOCs) to remain in force — introduces dependence on third-party approvals","Minimal standalone text but technical content is handled by referenced FAA documents (increases practical complexity for implementers)","No extensive nested exceptions within the Australian text itself"],"plain_english_summary":"**What this instrument does (mechanical change):**\n\n- Requires operators of certain Boeing 737 models to carry out the actions set out in the United States FAA Emergency Airworthiness Directive (AD) 2008-24-51. The Australian directive incorporates that FAA AD by reference (see “Requirement”).\n- Keeps the original compliance date unchanged and confirms that any exclusion or previously approved alternate method of compliance (AMOC) that was valid before this amendment remains valid (see “Compliance”).\n- Replaces the original text of the Australian AD with a version that expressly references the FAA AD; it also accepts FAA‑approved alternative compliance methods and points to FAA AD 2011‑18‑03 for the terminating action (see “Background”).\n\n**Who is affected:**\n\n- Operators/owners of Boeing 737-600, -700, -700C, -800 and -900 series aeroplanes *on which* Boeing Alert Service Bulletin (ASB) 737‑28A1206 (dated 11 Jan 2006) has already been accomplished (see “Applicability”).\n\n**What operators must do (behavioural change):**\n\n- Perform the inspections, wiring corrections and any other required actions exactly as specified in FAA Emergency AD 2008‑24‑51. If an operator already has an FAA‑approved alternate method of compliance, that AMOC remains acceptable here (see “Requirement” and “Compliance”).\n\n**Why it matters (safety mechanism):**\n\n- Investigations found miswiring of the centre wing tank (CWT) autoshutoff wiring on aeroplanes modified per Boeing ASB 737‑28A1206. When the flightcrew turns off the CWT pump switches, incorrect wiring can re‑energise the left pump while the low‑pressure lights go out — falsely indicating power is removed. That can leave the pump running dry, causing localized overheating and creating a potential ignition source inside the fuel tank (see “Background”). The mandated actions are intended to remove that incorrect wiring condition and thereby reduce the risk of pump‑related ignition inside the CWT.\n\n**Who pays and who decides:**\n\n- Airline/operators bear the direct costs: inspections, corrective wiring, parts, labour and associated aircraft downtime. The Civil Aviation Safety Authority (CASA), acting through this AD, requires compliance; the FAA AD’s detailed instructions determine the technical steps. FAA‑approved AMOCs remain acceptable, so the FAA’s approvals continue to influence acceptable options (see “Requirement” and “Compliance”).\n\n**Implementation, compliance and risk trade‑offs:**\n\n- Implementation depends on technical corrective work to wiring and testing defined by the FAA AD. The advisory notes that the functional tests previously specified in Boeing ASB 737‑28A1206 are inadequate to detect the incorrect wiring condition — so more intrusive inspection/wiring correction is required (see “Background”).\n- Costs: concentrated on the specific operators of affected aeroplanes (those with the ASB already embodied), including inspection and modification labour and aircraft out‑of‑service time. Benefits: safety improvement that accrues broadly to passengers, crew and the wider flying public. \n- Flexibility: FAA‑approved alternate methods of compliance remain acceptable, which reduces the risk that operators lack any pathway to comply if the exact FAA remedy is impractical. Terminating actions are detailed in FAA AD 2011‑18‑03 (referenced), so operators may be able to meet the AD permanently by following that later FAA action (see “Background”).\n\n**Practical notes for operators:**\n\n- Check which aircraft have Boeing ASB 737‑28A1206 embodied — only those aeroplanes are in scope (see “Applicability”).\n- If an FAA‑approved AMOC was already in force for your aeroplane before this amendment, it continues to be valid here (see “Compliance”).\n- Plan for inspection/rewiring work and aircraft downtime; document compliance against FAA AD 2008‑24‑51 (as incorporated) to meet CASA’s requirement.\n\n(References in parentheses refer to the labelled sections of the AD text you provided: “Applicability”, “Requirement”, “Compliance”, and “Background”.)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope precisely. The change is purely editorial/streamlining — replacing Australia's original detailed text with a reference to the FAA source document. The safety issue (CWT fuel pump wiring), affected aircraft models, and compliance obligations remain identical to the original 2008 directive."},"complexity_factors":["Short, single-purpose safety directive (approximately 400 words of substantive content)","Minimal defined terms (only standard aviation acronyms: CWT, ASB, FAA, AD)","Simple conditional applicability (specific Boeing models + specific service bulletin installation)","Single cross-reference to external FAA document (Emergency AD 2008-24-51) rather than internal legislative machinery","No nested exceptions or complex compliance calculations — compliance date unchanged from original, with straightforward grandfathering of existing alternative compliance methods","Clear causal chain in background section explaining the safety risk"],"plain_english_summary":"This AD requires owners/operators of certain Boeing 737 (-600/700/700C/800/900) to follow the FAA’s emergency AD to inspect and correct a wiring fault in the Centre Wing Tank fuel-pump system that can leave the left pump running dry (overheating and spark risk) despite “off” indications. It targets aircraft with Boeing SB 737‑28A1206 installed Jan 2006 or later. Amendment 1 removes Australia’s detailed text and instead references the FAA ADs (including terminating actions)."},"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-b737-347-amdt-1-centre-wing-tank-autoshutoff-wiring","history":"/api/acts/ad-b737-347-amdt-1-centre-wing-tank-autoshutoff-wiring/history","analysis":"/api/acts/ad-b737-347-amdt-1-centre-wing-tank-autoshutoff-wiring/analysis","conflicts":"/api/acts/ad-b737-347-amdt-1-centre-wing-tank-autoshutoff-wiring/conflicts","importantCases":"/api/acts/ad-b737-347-amdt-1-centre-wing-tank-autoshutoff-wiring/important-cases","documents":"/api/acts/ad-b737-347-amdt-1-centre-wing-tank-autoshutoff-wiring/documents"}}