{"id":"F2011L01843","name":"AD/B737/152 Amdt 1 - Centre Fuel Tank - Limitations","slug":"ad-b737-152-amdt-1-centre-fuel-tank-limitations","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":87141,"registerId":"commonwealth-F2011L01843-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/B737/152 Amdt 1 | Centre Fuel Tank - Limitations | 18/2011 |\n| ------------------ | ------------------------------ | ------- |\n\n| Applicability: | All Model 737 series aeroplanes. |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | Revise the Limitations Section of the Aircraft Flight Manual (AFM) to include the information detailed in FAA AD 2001-08-24 Amdt 39-12201. |\n| Compliance: | Date remains unchanged to that detailed in the original issue of this Directive.Despite the new AD/B737/152 Amdt 1, an exclusion or an alternate method of compliance that was in force before the coming into effect of AD/B737/152 Amdt 1 continues to be in force. |\n| | This Airworthiness Directive becomes effective on 30 September 2011. |\n| Background: | On 3 March 2001, a Boeing Model 737-400 series airplane caught fire and burned while parked at a bay at the Don Muang International Airport, Bangkok, Thailand. Although the accident investigation is ongoing and the probable cause of the accident has not been identified, the Government of Thailand, in conjunction with the United States National Transportation Safety Board, has determined that the centre tank exploded shortly after the main fuel tanks of the airplane were refuelled. It appears that the centre tank fuel pumps were operating dry (no fuel passing through them) at the time of the explosion.This accident is similar to a 1990 centre tank explosion on a Boeing Model 737-300 airplane. The ignition source of that explosion was never identified. The centre tank fuel pumps were operating dry at the time of that explosion.Extended dry operation of the centre tank fuel pumps, which occurred prior to both incidents, is contrary to the manufacturer’s procedures for safe operation of the fuel pumps. Extended dry pump operation can result in overheating and excessive wear of the pump bearings and consequent contact between rotating and nonrotating parts of the pumps. Both overheating of the bearings and contact between rotating and nonrotating parts have the potential to create an ignition source in the form of hot surfaces or sparks. In addition, during dry operation of the pumps, ignition of vapour in a fuel pump can create a flame front that can reach the fuel tank and cause a fuel tank explosion. |\n\n| | This Directive is issued to prevent ignition of fuel vapours due to the generation of sparks and a potential ignition source inside the centre tank caused by metal-to-metal contact during dry fuel pump operation, which could result in a fire or explosion of the fuel tank. This Directive requires revising the AFM to prohibit extended dry operation of the centre tank fuel pumps.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 action for the requirement of this AD.The original issue of this AD became effective on 10 May 2001.Alternative Methods of Compliance for AD 2001-08-24 Amdt 39-12201 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/B737/152 Amdt 1","sectionType":"part","heading":"AD/B737/152 Amdt 1","content":"## AD/B737/152 Amdt 1","sortOrder":1},{"sectionNumber":"Centre Fuel Tank - Limitations","sectionType":"part","heading":"Centre Fuel Tank - Limitations","content":"## Centre Fuel Tank - Limitations","sortOrder":2},{"sectionNumber":"18/2011","sectionType":"part","heading":"18/2011","content":"## 18/2011","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The amendment does not broaden or narrow the population of affected aircraft (still 'all Model 737 series aeroplanes') or the substantive obligation (revise AFM to prohibit extended dry centre-pump operation). It replaces the original AD text with a direct incorporation of the FAA AD for easier cross-reference, and preserves previously approved exclusions or alternate methods of compliance (Requirement; Compliance; Background)."},"complexity_factors":["Administrative update only: Requires revision of the AFM Limitations section rather than hardware modification, so technical complexity is low (Requirement: 'Revise the Limitations Section of the Aircraft Flight Manual (AFM) ...').","Broad applicability: Applies to all Model 737 series aeroplanes, so administrative effort scales with fleet size (Applicability: 'All Model 737 series aeroplanes').","Cross-reference dependency: Incorporates FAA AD 2001-08-24 by reference, creating reliance on an external document for the specific limiting text and for terminating actions (Requirement; Background: 'incorporates the original FAA AD by reference' and 'terminating action ... in FAA AD 2011-18-03').","Compliance clarity and continuity: Compliance date is unchanged and pre-existing exclusions or alternate methods of compliance remain in force, which reduces legal uncertainty but requires operators to review prior AMOCs (Compliance: 'Date remains unchanged ... an exclusion or an alternate method of compliance that was in force before ... continues to be in force').","Accepts FAA AMOCs: Alternative Methods of Compliance approved by the FAA are expressly acceptable, shifting some decision authority to FAA approvals (Background: 'Alternative Methods of Compliance ... approved by the FAA are acceptable').","Low enforcement technicality but non-trivial administrative burden: Regulators must verify AFM changes and operators must amend manuals and train crews; this is routine but time-consuming (Requirement; Compliance).","Risk-management rationale documented: The background links the AFM change to safety incidents involving dry pump operation and potential ignition sources, meaning the rule targets operational behaviour rather than design change (Background: description of incidents and ignition mechanisms).","Terminating action linkage: The amendment points to a separate FAA AD that details terminating action, so full compliance pathway may require following additional FAA material (Background: 'which details the terminating action for the requirement of this AD')."],"plain_english_summary":"This directive requires operators of all Boeing 737 series aeroplanes to update the Aircraft Flight Manual (AFM) Limitations section to include the FAA AD 2001-08-24 material, specifically prohibiting extended dry operation of the centre fuel tank pumps. The change is effective 30 September 2011.\n\nThe stated purpose is to reduce the risk of ignition or explosion in the centre fuel tank caused by pump overheating or metal-to-metal contact. Operators bear the cost and administrative burden of revising AFMs; FAA-approved alternative compliance methods remain acceptable."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The amendment maintains the original safety purpose (preventing centre tank explosions due to dry pump operation). The only change is administrative: replacing the original text with a reference to the FAA AD to facilitate easier tracking of related directives. The substantive safety requirement remains identical."},"complexity_factors":["Short, single-purpose directive with one primary requirement (AFM revision)","Minimal defined terms (relies on external FAA AD for technical specifics)","Simple conditional logic: original compliance date unchanged, existing exemptions preserved","Single cross-reference to external FAA AD rather than internal technical detail","No nested exceptions or complex operational scenarios within the text itself"],"plain_english_summary":"This AD requires all Boeing 737 operators in Australia to update their Aircraft Flight Manuals to add limits on centre fuel tank pumps and ban extended “dry running,” addressing a known ignition risk that caused past 737 tank explosions. The amendment aligns Australia with the referenced FAA AD (2001‑08‑24) for tracking related updates and preserves previously approved exemptions or alternative compliance—keeping the original compliance deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-152-amdt-1-centre-fuel-tank-limitations","history":"/api/acts/ad-b737-152-amdt-1-centre-fuel-tank-limitations/history","analysis":"/api/acts/ad-b737-152-amdt-1-centre-fuel-tank-limitations/analysis","conflicts":"/api/acts/ad-b737-152-amdt-1-centre-fuel-tank-limitations/conflicts","importantCases":"/api/acts/ad-b737-152-amdt-1-centre-fuel-tank-limitations/important-cases","documents":"/api/acts/ad-b737-152-amdt-1-centre-fuel-tank-limitations/documents"}}