{"id":"F2011L01845","name":"AD/B737/198 Amdt 2 - Centre Tank Fuel Pumps","slug":"ad-b737-198-amdt-2-centre-tank-fuel-pumps","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":87143,"registerId":"commonwealth-F2011L01845-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/B737/198 Amdt 2 | Centre Tank Fuel Pumps | 18/2011 |\n| ------------------ | ---------------------- | ------- |\n\n```html\n

Applicability:

All Model 737-600, -700, -700C, -800 and -900 series aeroplanes.

Requirement:

1. Model 737-600, -700, -700C, -800 and -900 series aeroplanes with a line number 1234 and below:

a. If not previously accomplished in accordance with the original issue of this Directive - Remove the Aircraft Flight Manual (AFM) revision required by AD/B737/190 Amdt 1.

b. If not previously accomplished in accordance with the original issue of this Directive - Revise the Limitations Section of the Aircraft Flight Manual (AFM) by incorporating the procedures included at Annex A to this Amendment (this may be accomplished by inserting a copy of Annex A into the AFM).

The limitations contained in this Amendment supersede any conflicting basic AFM limitations.

c. If not previously accomplished in accordance with the original issue of this Directive - Install a placard adjacent to each pilot's primary flight display (PFD) that reads as follows either:

\"AD/B737/198 fuel usage restrictions required\" or

\"AD 2002-19-52 fuel usage restrictions required\"

2. For all Model 737-600, -700, -700C, -800 and -900 series aeroplanes:

a. Fuel pumps with the following part numbers may not be installed on any aeroplane as a replacement part, unless the pump has been inspected to ensure that the wire bundle is properly routed in the pump since the most recent assembly of the end cap and motor-impeller housing (whether during manufacture, after maintenance or inspection, or after overhaul) in accordance with Boeing Alert Service Bulletin (ASB) 737-28A1197 dated 23 September 2002 or Crane Hydro-Aire Service Bulletin (SB) Crane Hydro-Aire Motor-Impeller-28-01, including Appendix A, dated
17 September 2002:

Hydro-Aire Part Number

60-989100-4
60-755100-4

Boeing Part Number

60B89004-14
60B92404-8

b. Fuel pump motor-impeller assembly having any part number may not be installed on any aeroplane in any pump position as a replacement part, unless the assembly has been inspected since the most recent assembly of the end cap motor-impeller housing (whether during manufacture, after maintenance or inspection, or after overhaul) using X-ray methods to ensure that the wire bundle is properly routed in the pump in accordance with Boeing ASB
737-28A1197 or Crane Hydro-Aire SB Crane Hydro-Aire
Motor-Impeller-28-01, including Appendix A.

3. Remove the Requirement 1.b. AFM revision and the Requirement 1.c. placard.

Note 1: Requirement 3 is optional terminating actions for the fuel usage restrictions at Requirements 1.b and c.

Note 2: FAA AD 2002-19-52 Amdt 39-12900 refers.

Compliance:

For Requirement 1 - Within 14 days after the effective date of this Amendment.

Despite the new AD/B737/198 Amdt 2, an exclusion or alternate method of compliance that was in force before the coming into effect of AD/B737/198 Amdt 2 continues to be in force.

For Requirement 2 - As of the effective date of this Amendment.

For Requirement 3 - When all fuel pumps for the centre wing tank, horizontal stabilizer tank, centre auxiliary tanks, together with auxiliary fuel tanks 1 and 4 on an aeroplane have been inspected using X-ray methods in accordance with Boeing ASB 737-28A1197 or Crane Hydro-Aire SB Crane Hydro-Aire Motor-Impeller-28-01, including Appendix A.

Inspection of a pump by Crane Hydro-Aire before the effective date of the original issue of this Directive is considered equivalent to an inspection performed in accordance with Crane Hydro-Aire SB Crane Hydro-Aire Motor-Impeller-28-01, including Appendix A.

Inspection of a pump in accordance with Boeing ASB 737-28A1197 or Crane Hydro-Aire SB Crane Hydro-Aire Motor-Impeller-28-01, including Appendix A, before the effective date of the original issue of this Directive is acceptable for removal of the AFM revision and placard.

Date remains unchanged to that detailed in Amendment 1 of this Directive.

This Amendment becomes effective on 30 September 2011.

Background:

The United States Federal Aviation Administration (FAA) has received reports indicating that fuel pumps on Boeing Model 737, 747 and 757 series aeroplanes have failed as a result of chafing of the stator lead wire bundle. This occurred when the stationary wire bundle came into contact with the rotor in the pump motor. The pumps failed when the pump power was short-circuited to the rotor and the circuit protection device tripped.

Examination of failed pumps showed that arcing had occurred in the pump bearings both inside and outside of the explosion-proof cavity of the pump. Such arcing could result in an ignition source in the fuel tank. The fuel pump failures have been attributed to the manufacturing assembly process during which the stator lead wire bundle was improperly installed and positioned in the end cap.

The original issue of this Directive superseded AD/B737/190 Amdt 1, which was cancelled. The Directive required an amendment to the AFM which is intended to ensure that the centre tank pump inlets are covered with fuel during pump operation, preventing fuel vapours from coming into contact with any ignition source resulting from a fuel pump failure and installation of a placard adjacent to both PFDs advising that fuel usage restrictions apply. The Directive also provided optional terminating action for Requirements 1.b. and c.

This Amendment limits the applicability of the fuel usage restrictions to aeroplanes before line number 1234, whilst at the same time retaining the requirement to ensure that fuel pumps that have not been inspected are not installed on aeroplanes as replacement spares.

Amendment 2 allows alternate wording for the placard detailed in Requirement 1 (c). This is to allow easier cross referencing to FAA AD 2011-18-03 which details alternative terminating actions for the requirements of this AD.

Alternative Methods of Compliance for AD 2002-19-52 that are approved by the FAA are acceptable as a means of compliance against this AD.

The original issue of this Directive became effective on 3 October 2002.

Amendment 1 of this Directive became effective on 23 June 2005.

\n```\n\n![](image.001.png)\n\nMike Higgins \nDelegate of the Civil Aviation Safety Authority\n\n5 September 2011\n\n| AD/B737/198 Amdt 2Annex A | Centre Tank Fuel Pumps | 18/2011 |\n| ------------------------- | ---------------------- | ------- |\n\nModel 737-600, -700, -700C, -800 and -900 \nSeries Aeroplanes \nAircraft Flight Manual Revision\n\nCertificate Limitations\n\nThe centre tank fuel pumps must be OFF for takeoff if centre tank fuel is less than 5,000 pounds (2,300 kilograms) with the airplane readied for initial taxi.\n\nBoth centre tank fuel pump switches must be selected OFF when centre tank fuel quantity reaches approximately 1,000 pounds (500 kilograms) during climb and cruise or 3,000 pounds (1,400 kilograms) during descent and landing. The fuel pumps must be positioned OFF at the first indication of fuel pump low pressure.\n\nThe CWT fuel quantity indication system must be operative to dispatch with CWT mission fuel.\n\nNote: The CONFIG indicator will annunciate when centre tank fuel exceeds 1,600 pounds (800 kilograms) and the centre tank fuel pump switches are OFF. Do not accomplish the CONFIG non-normal procedure prior to or during takeoff with less than 5,000 pounds (2,300 kilograms) of centre tank fuel or during descent and landing with less than 3,000 pounds (1,400 kilograms) of centre tank fuel.\n\nNote: In a low fuel situation, both centre tank pumps may be selected ON and all centre tank fuel may be used.\n\nIf the main tanks are not full, the zero fuel gross weight of the airplane plus the weight of centre tank fuel may exceed the maximum zero fuel gross weight by up to 5,000 pounds (2,300 kilograms) for takeoff, climb and cruise and up to 3,000 pounds (1,400 kilograms) for descent and landing, provided that the effects of balance (CG) have been considered.\n\nIf a centre tank fuel pump fails with fuel in the centre tank, accomplish the FUEL PUMP LOW PRESSURE non-normal procedure.\n\nWhen defuelling centre or main wing tanks, the Fuel Pump Low Pressure indication lights must be monitored and the fuel pumps positioned to OFF at the first indication of fuel pump low pressure. Defuelling with passengers on board is prohibited.","sortOrder":0},{"sectionNumber":"AD/B737/198 Amdt 2","sectionType":"part","heading":"AD/B737/198 Amdt 2","content":"## AD/B737/198 Amdt 2","sortOrder":1},{"sectionNumber":"Centre Tank Fuel Pumps","sectionType":"part","heading":"Centre Tank Fuel Pumps","content":"## Centre Tank Fuel Pumps","sortOrder":2},{"sectionNumber":"18/2011","sectionType":"part","heading":"18/2011","content":"## 18/2011","sortOrder":3},{"sectionNumber":"AD/B737/198 Amdt 2Annex A","sectionType":"part","heading":"AD/B737/198 Amdt 2Annex A","content":"## AD/B737/198 Amdt 2 \nAnnex A","sortOrder":4}],"analysis":{"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":6,"scope_assessment":{"changed":true,"description":"The original directive (2002) imposed flight manual restrictions and placard requirements on all affected Boeing 737 aircraft. Amendment 2 significantly narrows the scope by limiting these operational restrictions to only aircraft with line numbers 1234 and below, while maintaining the parts installation ban across all aircraft. This represents a scope reduction from universal operational restrictions to targeted restrictions based on manufacturing lineage, reflecting improved understanding of which aircraft are most at risk."},"complexity_factors":["Multiple nested applicability conditions: different requirements apply based on aircraft line number (1234 and below vs all aircraft)","Cross-references to three external documents: Boeing Alert Service Bulletin 737-28A1197, Crane Hydro-Aire Service Bulletin Motor-Impeller-28-01, and FAA AD 2002-19-52","Conditional compliance logic: Requirement 3 is optional terminating action that removes Requirements 1.b and 1.c, but only after specific X-ray inspections of multiple fuel tank systems","Specific part number prohibitions with exception conditions (4 part numbers listed across 2 manufacturers)","Grandfathering provisions: recognises pre-existing inspections and alternate compliance methods approved by FAA","Technical operational requirements in Annex A with multiple weight thresholds (5,000/2,300 kg, 1,000/500 kg, 3,000/1,400 kg) varying by flight phase","Amendment structure requires understanding of previous versions (original issue, Amendment 1, Amendment 2) and their interaction"],"plain_english_summary":"This CASA Airworthiness Directive targets centre tank fuel-pump wiring chafing that can cause arcing and ignite fuel vapour on Boeing 737-600/-700/-700C/-800/-900 aircraft. It mandates flight-manual fuel-pump operating procedures and cockpit placards for older aircraft (line ≤1234), and prohibits installing replacement pumps or motor-impeller assemblies unless X‑ray inspected for correct wire routing. Operators may remove the procedural restrictions once all relevant tanks’ pumps are X‑ray inspected per Boeing/Crane service bulletins. Non‑compliance grounds affected aircraft."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 2 narrows the operational (fuel usage) requirements compared with the original Directive by limiting the AFM revision and placard requirement to aeroplanes with line number 1234 and below, while retaining and in some respects strengthening maintenance controls across the fleet. It also introduced alternative placard wording and explicit acceptance of FAA-approved alternate methods of compliance. Mechanically, the Amendment reduced the set of aeroplanes subject to the immediate operational limitations but kept the inspection/parts‑installation prohibition applicable more broadly; it therefore changed the practical scope from a fleet‑wide operational restriction to a targeted operational restriction plus a fleet‑wide parts/inspection control."},"complexity_factors":["Applicability split by line number (line number 1234 threshold) — conditional scope","Three distinct requirement types (operational AFM/placard; parts‑installation/inspection; optional terminating action)","Cross-references to external service documents (Boeing ASB 737-28A1197; Crane Hydro‑Aire SB Motor‑Impeller‑28‑01 including Appendix A)","Mandatory X‑ray inspection method for motor‑impeller assemblies (technical inspection requirement)","Optional terminating action contingent on completion of inspections across multiple tanks/pumps (dependency across multiple components)","Alternate placard wording permitted (minor variance allowed)","References to prior FAA ADs and acceptance of FAA AMOCs (inter-agency cross-acceptance)","Multiple compliance timeframes (14 days for Requirement 1; immediate for Requirement 2; contingent timing for Requirement 3)","Notes on prior equivalent inspections (pre‑existing Crane inspections accepted) introduce conditional acceptability"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Applies to Boeing 737-600, -700, -700C, -800 and -900 aeroplanes.\n- For aeroplanes with line number 1234 and below it requires (Requirement 1):\n - Amend the Aircraft Flight Manual (AFM) to add the fuel-usage/operation limits in Annex A (or insert Annex A into the AFM).\n - Install a placard next to each pilot's primary flight display that notifies crews that the AD fuel-usage restrictions apply (two alternative wordings are permitted).\n - These AFM limitations override any conflicting basic AFM limits.\n- For all applicable aeroplanes (Requirement 2):\n - Prohibits fitting certain centre-tank fuel pump part numbers as replacement parts unless the pump has been inspected to confirm the internal wire bundle is correctly routed, in accordance with Boeing Alert Service Bulletin (ASB) 737-28A1197 or Crane Hydro‑Aire Service Bulletin Motor‑Impeller‑28‑01 (including Appendix A).\n - Requires any fuel-pump motor‑impeller assembly installed as a replacement to have been inspected by X‑ray using those same service bulletins.\n- Optional terminating action (Requirement 3):\n - Once all centre and auxiliary tank pumps on an aeroplane have been X‑ray inspected in accordance with the Boeing or Crane service bulletins, the AFM revision and the placard required by Requirement 1 may be removed.\n\n**Who is affected**\n\n- Aircraft operators / airworthiness managers of Boeing 737-600/-700/-700C/-800/-900 series aircraft.\n- Maintenance, repair and overhaul (MRO) organisations that inspect, overhaul or supply replacement fuel pumps and motor‑impeller assemblies.\n- Pilots and flight crews (operational limitations and placards affect dispatch/operation decisions).\n\n**Why it matters (stated purpose and the safety mechanism)**\n\n- Stated purpose: The FAA received reports that certain centre‑tank fuel pumps failed because stator lead wires were chafing against the rotor; that chafing caused arcing and pump failures that could create an ignition source inside a fuel tank. The AD aims to reduce the risk of a pump‑related ignition in fuel tanks by:\n - restricting when centre tank pumps may be used (so pump inlets remain submerged when pumps run), and\n - ensuring pumps and motor‑impeller assemblies are inspected (including X‑ray) so the internal wire bundle is correctly routed and cannot chafe.\n\n**How it works in practice (costs, incentives, trade‑offs, implementation points)**\n\n- Who pays: aircraft operators and their MRO contractors pay for AFM revisions, placards, inspections (including X‑ray), and any corrective work. There is also potential operational cost from fuel‑loading restrictions (see Annex A).\n- Behaviour changes required:\n - Crews must follow tighter fuel‑pump usage rules (Annex A) — e.g. centre tank pumps off for takeoff below a specified centre‑tank fuel weight, and pumps switched off at low‑fuel indications.\n - Maintenance organisations must inspect existing pumps (and any candidate spare) per the Boeing/Crane SBs before installation; motor‑impeller assemblies require X‑ray inspection.\n - Operators are incentivised to complete the X‑ray inspections fleet‑wide to remove the operating restrictions and the placard (optional terminating action).\n- Compliance burden and operational trade‑offs:\n - AFM and placarding changes are low administrative cost but create firm operational limits that may reduce usable payload or require different fuel‑loading plans on affected flights (Annex A lists weight thresholds and conditions where pumps must be off).\n - X‑ray inspections and possible rework/overhaul are direct maintenance costs and can cause aircraft out‑of‑service time. Availability of qualified X‑ray inspection facilities and trained personnel may be a constraint.\n - MROs and spare‑part managers must track which pumps are inspected and may be unable to fit otherwise serviceable spares until inspected, creating spare‑pool management costs.\n- Implementation risk and technical limits:\n - The safety outcome depends on the reliability of the inspection procedures (including X‑ray) to detect mis‑routed wire bundles. The AD accepts prior Crane inspections done before the original Directive as equivalent (reduces repeat work for some parts).\n - The AD cross‑references Boeing and Crane service bulletins and FAA ADs; reliance on those external documents means operators must maintain up‑to‑date copies and follow their procedures precisely.\n- Incentives and concentrated effects:\n - Benefit is concentrated (reduced risk of ignition in a fuel tank) and concentrated costs fall on operators of older line‑number aircraft, and on MROs that handle these pumps. Operators are incentivised to finish inspections to remove operational restrictions (a clear private benefit from incurring inspection cost).\n- Regulatory flexibility:\n - The AD allows previously approved exclusions or alternate methods of compliance (AMOCs) that were in force before this amendment to continue, and it accepts FAA‑approved AMOCs as acceptable means of compliance (reduces duplication for operators already compliant with FAA approvals).\n\n**Key timing and practical notes**\n\n- Requirement 1 (AFM revision and placard for line numbers ≤ 1234): compliance within 14 days after this Amendment's effective date.\n- Requirement 2 (inspection requirement for replacement pumps and X‑ray requirement for motor‑impeller assemblies): effective immediately as of the Amendment's effective date for installations.\n- Requirement 3 (removal of AFM revision and placard) becomes available once all relevant pumps on an aeroplane have been X‑ray inspected per the Boeing or Crane SBs.\n- The Amendment narrows the AFM/placard applicability to aeroplanes before line number 1234 while keeping the inspection/installation controls for all aeroplanes.\n\n(References: Requirement 1, Requirement 2, Requirement 3, Annex A, Compliance and Background sections of AD/B737/198 Amdt 2.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-198-amdt-2-centre-tank-fuel-pumps","history":"/api/acts/ad-b737-198-amdt-2-centre-tank-fuel-pumps/history","analysis":"/api/acts/ad-b737-198-amdt-2-centre-tank-fuel-pumps/analysis","conflicts":"/api/acts/ad-b737-198-amdt-2-centre-tank-fuel-pumps/conflicts","importantCases":"/api/acts/ad-b737-198-amdt-2-centre-tank-fuel-pumps/important-cases","documents":"/api/acts/ad-b737-198-amdt-2-centre-tank-fuel-pumps/documents"}}