AD/B747/201 Amdt 3 - Centre Fuel Tank Wiring and Components

The Directive organises around a small set of technical interventions and compliance mechanics. The principal concepts are:

• Applicability by airframe line number: the AD applies only to Boeing Model 747 aeroplanes with line numbers 1-1124 inclusive (Applicability). This confines the mandatory scope to a defined production run.

• One‑time inspection and testing regime: Requirement 1 mandates a one‑time visual inspection of centre fuel tank wiring and components to detect discrepancies including damage, disbonding or incorrect installation, together with a one‑time electrical bonding test of centre fuel tank components. The AD defines a "visual inspection" as a general visual inspection, with the parameters of that inspection set out in Note 1.

• Corrective action conditional on findings: If the visual inspection reveals discrepancy, Requirement 2 requires repair or replacement. If the electrical bonding test reveals resistance above service bulletin limits, Requirement 3 requires rework per the bulletin. The AD therefore uses conditional obligations to force remedial work where tests show nonconformance.

• Parallel FQIS requirements: Requirement 4 sets a separate sequence for FQIS: an insulation resistance test, a visual inspection of FQIS wiring and components for chafing or incorrect terminal block configuration, replacement of FQIS probes with new or serviceable components as specified in Figure 5 of the ASB, and a system adjustment and operational test. Requirement 5 ties corrective action to any discrepancies found during Requirement 4 inspections or tests.

• Hardware modification for selected lines: Requirement 6 mandates installation of a flame arrestor in the inlet line of the electrical motor‑operated scavenge pump of the centre fuel tank, but only for aeroplanes having line positions 1 through 971 inclusive.

• Prescribed means of compliance via manufacturer service documents: The AD requires accomplishment "in accordance with" specific Boeing Service Bulletins and Alert Service Bulletins and names acceptable revisions for each task. It also recognises earlier work done under SB 747‑28‑2205 dated 27 June 1997 as acceptable for corresponding actions, with explicit exclusions for actions not described in that earlier bulletin (Note 2).

• Use of FAA material and AMOCs: The Directive is explicitly based on FAA AD 99‑08‑02 and references FAA AD and AMOCs (Note 5). Amendments introduced alternate methods of compliance reflecting FAA AMOCs; the operative text of the current amendment incorporates an AMOC for Requirements 1-3 as noted in the Background.

• Compliance timing: The compliance section prescribes timing, including "within 24 months after the effective date of the original issue" for several Requirements, and "before further flight" for remedial actions triggered by detected discrepancies. The AD identifies the original issue effective date as 17 June 1999 and records amendment effective dates (Compliance; end of instrument).

These concepts structure the Directive as a mix of diagnostic (inspect and test), corrective (repair, replace, rework), and preventive hardware modification measures, implemented by reference to manufacturer procedures and accepted alternate compliance paths from the FAA.

The AD identifies its primary regulatory targets explicitly by applicability and implied operational responsibilities. The affected parties are:

• Aircraft owners and operators of Boeing Model 747 aeroplanes with line numbers 1 through 1124 inclusive, because the Applicability clause names those aeroplanes as the subjects on which these mandatory actions must be taken.

• Maintenance organisations, engineers and technicians who will perform the inspections, electrical bonding tests, insulation resistance tests, component replacements, system adjustments and the installation of flame arrestors, because Requirement 1 through 6 prescribe specific maintenance and modification tasks "in accordance with" the Boeing service documents referenced.

• Aircraft certificating and continuing airworthiness authorities within the operator's compliance chain, because this AD is issued under CASA authority, and compliance with the AD will be a condition of continuing airworthiness. The top matter shows the AD was issued by the CASA delegate named and signed, invoking subregulation 39.1(1) of CASR 1998 as the statutory basis for issuing the AD.

• Supply and parts providers who supply new or serviceable components, notably FQIS probes and flame arrestors, because Requirement 4.c and Requirement 6 require replacement with new or serviceable components and installation of specified hardware.

• Organisations tracking airworthiness compliance (for example fleet compliance managers and auditors), because the AD prescribes time limits tied to the original issue effective date and refers to specific figure references in Boeing ASBs/SBs, which affect how a compliance record will be evidenced.

The AD’s mapping of who is responsible for compliance is implicit rather than spelled out in a duties‑and‑rights framework: the instrument prescribes actions to be "accomplished" in accordance with specified service bulletins. The practical implication is that operators and maintenance organisations must arrange inspections and tests and must undertake repairs or replacements where required. The AD does not itself allocate payment responsibility, but the obligations will fall on the operator or owner who must cause the work to be done to remain compliant with the AD and with CASA’s continuing airworthiness regime.

The Directive creates operational duties and prescribes permitted methods of compliance. The main duties and prescribed rights under the AD are:

• Duty to inspect: Requirement 1.a requires a one‑time visual inspection of centre fuel tank wiring and components to detect discrepancies, and Note 1 provides the definition of "visual inspection" used in the Directive. The "visual inspection" is defined as a general visual inspection and may require removal of access panels, use of lighting and physical access aids such as stands or ladders; therefore the duty includes reasonable actions necessary to achieve the inspection objective.

• Duty to test electrical bonding: Requirement 1.b requires a one‑time electrical bonding test of the centre fuel tank components. The AD further ties corrective action thresholds to the limits specified in the service bulletin (Requirement 3), so the duty is both to perform the test and to compare measured values with the bulletin limits.

• Duty to repair or replace on finding discrepancies: Requirement 2 directs that if any discrepancy is detected by the visual inspection in Requirement 1.a, the operator must either repair the discrepant component or replace it with a new or serviceable component. Requirement 3 directs rework in the event electrical bonding test resistance exceeds bulletin limits.

• FQIS‑related duties: Requirement 4 obliges operators to conduct an insulation resistance test of the FQIS, a visual inspection of FQIS wiring and components to detect chafing, damage or incorrect terminal block configuration, replacement of specified FQIS probes with new or serviceable components as detailed in Figure 5 of the ASB, and a system adjustment and operational test. Requirement 5 requires corrective actions in accordance with the ASB when discrepancies are detected.

• Duty to install flame arrestor for specified lines: Requirement 6 requires installation of a flame arrestor in the inlet line of the electrical motor‑operated scavenge pump of the centre fuel tank for aeroplanes having line positions 1 through 971 inclusive, in accordance with ASB 747‑22A2210 dated 14 May 1998.

• Right to use specified compliance documents and revisions: The AD expressly permits compliance "in accordance with" listed Boeing SBs and ASBs and identifies allowable revisions for those documents (Requirement 1, Requirement 4, Requirement 6). That creates a permitted method of compliance, i.e., following those documents meets the AD obligation.

• Right to rely on prior actions done under earlier SB: Note 2 grants that actions performed in accordance with SB 747‑28‑2205 dated 27 June 1997, accomplished prior to the effective date of the Directive or its original issue, are considered acceptable for compliance only with corresponding actions in the Directive, subject to exclusions identified in Note 2. This is a limited grandfathering right.

• Conditional timing obligations: The AD sets timeframes as rights/duties: some inspections and installations must be accomplished "within 24 months after the effective date of the original issue" (Compliance items 1, 4 and 6), whereas if discrepancies are found, the AD requires that repairs or rework be performed "before further flight" (Compliance items 2, 3 and 5). The AD therefore imposes urgent corrective duties where nonconformance is found.

• Reference to AMOCs: The Background and notes state that FAA AD 99‑08‑02 and particular FAA AMOCs refer and that Amendments introduced AMOCs for certain Requirements, including the current amendment introducing an AMOC for Requirements 1, 2 and 3. That gives operators a pathway to seek or adopt an alternate method where authorised, subject to the terms of the AMOC as referenced.

The AD does not in its text itemise administrative rights such as an express appeals process against the AD itself, nor specific recordkeeping obligations. Instead, the instrument sets technical duties and identifies acceptable compliance documents and timelines. The rights to use particular document revisions and to rely on some prior work are set out explicitly, but any broader discretionary rights or procedural review routes would be outside the AD text and are not specified here.

The AD text provides the statutory basis for issuance but does not itself enumerate monetary fines or a sanction schedule. The instrument begins by stating it is issued "under subregulation 39.1 (1) of CASR 1998" and that the CASA delegate revokes the prior amendment and issues the AD (opening paragraph). That statement locates the AD within CASA’s regulatory authority, and implies enforcement and sanctioning powers lie in the referenced CASR provisions rather than in the AD text itself.

Within the AD, enforcement mechanics are indirect. The AD prescribes mandatory actions, acceptable methods of compliance, and clear compliance times: certain inspections and installations must be accomplished within 24 months after the effective date of the original issue of the Directive, and corrective actions where discrepancies are found must be carried out before further flight (Compliance section). Practically, these directives create a compliance obligation that an operator must fulfil to maintain an airworthy certificate and to operate the aircraft lawfully. The AD itself does not state the consequence of failing to comply; however the requirement that corrective actions be accomplished "before further flight" indicates a non‑compliant aircraft would not be authorised to fly pending remediation, because the AD explicitly links remedial action with flight status.

The AD references FAA material and AMOCs, and the Notes identify FAA AD 99‑08‑02 R1 Amdt 39‑11215 and AMOC references (Note 5). Amendments introduced alternate methods of compliance reflecting FAA AMOCs for specified Requirements, which indicates that CASA recognises certain FAA AMOCs as relevant. The AD does not describe how an operator may obtain or exercise an AMOC in Australia, nor does it specify who authorises AMOCs in CASA’s system; those procedural particulars are not contained in the AD and would be governed by CASA processes referenced only by the AD’s initial invocation of CASR authority.

Summary: The AD imposes mandatory technical obligations and timeframes under CASA authority, but the instrument itself does not specify penalty amounts or enforcement procedures. Enforcement and penalties, and processes for authorising alternate methods of compliance, are located in the broader statutory and regulatory framework referenced by the AD and not in the text provided here.

The AD situates itself within the CASA regulatory framework by explicit reference to subregulation 39.1(1) of CASR 1998 in the issuing paragraph. That identifies the AD as an instrument issued under CASA’s statutory rulemaking or safety directive power. The AD also expressly aligns with an FAA action: the Background states the Directive is based on Federal Aviation Administration AD 99‑08‑02, and Note 5 lists FAA AD 99‑08‑02 R1 Amdt 39‑11215 and specific FAA AMOCs as references. The instrument therefore interacts with foreign regulator action by adopting the FAA’s findings and by accepting certain FAA AMOCs as relevant.

Several interactions within the service‑document ecosystem are also important. The AD prescribes compliance "in accordance with" specific Boeing Service Bulletin and Alert Service Bulletin revisions. For certain tasks, it accepts either of two revisions (for example, SB 747‑28‑2205 Revision 1 dated 16 April 1998 or Revision 2 dated 17 May 1999). It also recognises prior work performed under an earlier SB dated 27 June 1997 as meeting corresponding obligations, but with explicit exclusions for actions not described in the earlier bulletin (Note 2). These cross‑references mean that an operator’s compliance status will be assessed against the combination of CASA AD requirements and the contents of the specified Boeing documents; the AD therefore creates a legal‑technical relationship between CASA regulatory requirements and manufacturer technical instructions.

The AD’s references to FAA AMOCs and FAA ADs create an interaction where alternate compliance permissions granted by the FAA are acknowledged in the CASA instrument. The Background and Note 5 state that the AD is based on FAA AD 99‑08‑02, and Amendments 1 and 2 introduced AMOCs reflecting FAA AMOCs for some Requirements; the current amendment introduces an AMOC for Requirements 1-3 reflecting an FAA AMOC. The AD does not detail the administrative mechanism by which those AMOCs operate in Australia, but the explicit cross‑reference indicates that FAA determinations influenced CASA’s permissible compliance approaches.

The AD does not itself modify or override the Boeing service documents it references; rather it mandates compliance with particular procedures in those documents. Consequently, any legal interplay with manufacturer warranties, parts procurement contracts, or maintenance agreements will depend on how those private contracts allocate responsibility for compliance with mandatory airworthiness directives. The AD text does not allocate payment or express contractual effects, and so the interaction with private contract law or commercial arrangements is an external matter not resolved in the AD itself.

Finally, the AD’s compliance timing language references the "effective date of the original issue" and records amendment effective dates. That creates an interaction between the AD’s lifecycle and earlier or later regulatory instruments: compliance deadlines in this AD are linked to the original issue date (17 June 1999) even though the current amendment became effective on 23 December 2004. Operators must therefore track both the AD’s amendment history and its original effective date to determine compliance windows.

The AD text documents a sequence of issues and amendments. The instrument begins by stating it revokes AD/B747/201 Amdt 2 and issues the present AD as Amdt 3. The end of the AD records effective dates for the original issue and successive amendments as follows:

• Original issue of the Airworthiness Directive became effective on 17 June 1999. That original issue is referenced repeatedly in the Compliance section as the baseline effective date for several compliance timeframes.

• Amendment 1 became effective on 2 December 1999. The Background notes describe the content of Amendment 1: it clarified Requirement 4.c by replacing the terms "series 3" and "series 4" with a reference to a figure in the Boeing Alert Service Bulletin, and it added the definition of "visual inspection" used in the Directive as Note 1.

• Amendment 2 became effective on 6 September 2000. The Background states Amendment 2 introduced an AMOC for Requirements 4 and 5 reflecting a Federal Aviation Administration AMOC.

• The current Amendment 3 (the instrument presented) became effective on 23 December 2004. The Background states this amendment introduces an alternate method of compliance for Requirements 1, 2 and 3 reflecting a Federal Aviation Administration AMOC.

The AD also includes Note 5 referencing FAA AD 99‑08‑02 R1 Amdt 39‑11215 and specific FAA AMOCs (AMOC 99‑140S‑177 dated 17 May 1999 and AMOC 99‑140S‑282 dated 11 August 1999). The Background identifies the Directive as being based on FAA AD 99‑08‑02, prompted by design review and testing conducted in support of an accident investigation.

The AD records that the current instrument is signed by the CASA delegate, James Coyne, on 11 November 2004, and that "This Amendment becomes effective on 23 December 2004" (signature block and subsequent statement). The AD further records that "The above AD is notified in the Commonwealth of Australia Gazette on 1 December 2004." Those entries provide documentary evidence of the AD’s administrative timeline and notification.

The amendment history therefore shows iterative refinement: clarification of technical references and inspection definitions in Amendment 1, addition of FAA‑based AMOC paths in Amendment 2, and the introduction of further AMOC recognition in Amendment 3. The AD text makes clear which actions are grandfathered from earlier service bulletins and which additional inspection and testing items were added in later revisions, notably the inclusion of inspection and testing of body fuel tank components described in Revision 1 of SB 747‑28‑2205 (Note 2).

The AD text itself does not record any litigation or judicial decisions. It refers to regulatory actions by CASA and to FAA ADs and AMOCs. The Background notes the FAA AD 99‑08‑02 was prompted by a design review and testing obtained in support of an accident investigation, but the AD does not identify or name any court proceedings, administrative adjudications, or appeals related to the Directive. The instrument likewise does not cite any legal cases or decisions that interpreted the AD.

Where the AD references FAA ADs and AMOCs, it does so as technical and regulatory sources rather than as litigated authorities. The absence of litigation references in the text means that, on the face of the AD, there is no recorded litigation history attached to this Directive. Any judicial or administrative challenges to the AD or to CASA’s use of the referenced CASR subregulation, or any disputes arising out of compliance obligations, are not documented in the AD itself and are therefore outside the source provided.

Because the AD does not include litigation history, operators and counsel seeking precedent or case law must look beyond this Directive to the broader record of CASA decisions, FAA proceedings, or court reports, none of which are reproduced or summarised in this AD text.

The AD text contains several technical and administrative traps for operators and maintainers that are explicit in the instrument’s wording and notes. Key items to watch are:

• Applicability versus modification scope: The AD applies to Model 747 aeroplanes line numbers 1-1124 inclusive, yet Requirement 6, the flame arrestor installation, applies only to aeroplanes having line positions 1 through 971 inclusive. Operators with line numbers 972-1124 are within the AD’s applicability but are not required by Requirement 6 to install the flame arrestor. That split scope can be a source of confusion if fleet tracking systems assume uniform action across all affected airframes.

• Compliance deadlines referenced to the original issue effective date: Several compliance times are expressed as "within 24 months after the effective date of the original issue of this Directive" (Compliance items 1, 4 and 6). The AD records the original issue effective date as 17 June 1999. The current amendment became effective on 23 December 2004. Operators relying on the amendment date rather than the original effective date may miscalculate deadlines. The AD explicitly ties compliance windows to the original issue date rather than to the amendment effective date.

• Interplay of service bulletin revisions and exclusions: The AD permits compliance in accordance with specific SB and ASB revisions, but Note 2 clarifies that actions on older SB 747‑28‑2205 dated 27 June 1997 are acceptable only for corresponding actions and explicitly excludes some actions that are not described in the earlier bulletin, such as inspection and testing of body fuel tank components described in Revision 1 of SB 747‑28‑2205. Operators relying on older SB compliance must verify whether a given action is covered by the older bulletin or is excluded.

• Reliance on figure references instead of series numbers: Amendment 1 replaced the terms "series 3" and "series 4" with references to a figure in the Boeing ASB to clarify Requirement 4.c. However, using figure references creates sensitivity to bulletin revisions that renumber or redraw figures. Operators must ensure they are using the exact figure in the ASB revision that the AD authorises (ASB dated 14 May 1998 or Revision 1 dated 26 August 1999).

• Definition of "visual inspection" is narrow and task‑specific: Note 1 defines "visual inspection" as a general visual inspection with specific lighting and access parameters. That definition instructs that some inspections may require removal of access panels or use of stands and ladders, and that inspection is limited to detection of "obvious damage, failure or irregularity". Inspectors should be aware that the AD’s definition prescribes a particular inspection standard and that more invasive inspection techniques may not be required by the AD unless the service bulletin specifies them.

• Conditional "before further flight" obligations can ground aircraft: Requirements 2, 3 and 5 require that corrective repairs or rework prompted by detected discrepancies be accomplished "before further flight". That means detection of a discrepancy during inspection or test creates an immediate obligation to remedy the condition prior to any further flight, which may require grounding the aircraft until the work is completed.

• AMOC reliance: The AD references FAA AMOCs and indicates that Amendments introduced AMOCs reflecting FAA AMOCs for certain Requirements. The AD does not set out the administrative process by which CASA authorises or recognises AMOCs in Australia, so operators planning to rely on an AMOC must confirm the Australian acceptance path and keep documentary authority for that AMOC.

• Cross‑document dependencies and figure references: Requirement 4.c requires replacement of FQIS probes "as detailed in Figure 5 of either ASB 747‑28A2208 dated 14 May 1998 or Revision 1 dated 26 August 1999". Compliance therefore depends on accessing the correct ASB and the correct figure, and any variation between revisions can affect which components or part numbers are required for compliance.

• Recordkeeping and proof of compliance not specified: The AD does not prescribe the form of compliance records or the documentation required to demonstrate that the required inspections, tests and corrective actions were completed. Operators should not assume the AD relieves them of any maintenance record obligations under CASA rules, but the AD itself does not specify recordkeeping format or retention periods.

These items are explicit in the AD’s text and notes, and each represents a practical compliance risk if not addressed in maintenance planning and fleet compliance systems.

The AD prescribes concrete steps and referenced documents as the authorised path to compliance. A practical compliance checklist based on the AD text follows, with references to the relevant Requirements and Notes:

1. Confirm applicability: Verify that the aircraft is a Boeing Model 747 with a line number between 1 and 1124 inclusive (Applicability). For Requirement 6, also check whether the aircraft’s line position is 1-971 inclusive, because the flame arrestor installation applies only to that subset.

2. Select authorised service documentation: For centre fuel tank wiring inspections and bonding tests comply with SB 747‑28‑2205 Revision 1 dated 16 April 1998 or Revision 2 dated 17 May 1999 (Requirement 1). For FQIS tasks comply with ASB 747‑28A2208 dated 14 May 1998 or Revision 1 dated 26 August 1999 (Requirement 4). For installation of the flame arrestor use ASB 747‑22A2210 dated 14 May 1998 (Requirement 6). If earlier work was done in accordance with SB 747‑28‑2205 dated 27 June 1997 before the effective date of the Directive, confirm whether those actions satisfy the corresponding parts of the Directive, taking into account Note 2 exclusions.

3. Schedule work within the required timeframe: The AD’s compliance section requires completion of certain items "within 24 months after the effective date of the original issue" of the Directive (Compliance items 1, 4 and 6), and it sets "before further flight" deadlines for required corrective actions discovered during inspection or testing (Compliance items 2, 3 and 5). The AD records the original issue effective date as 17 June 1999; operators should map those timeframes against their operational schedules and maintenance availability.

4. Conduct the visual inspection and electrical bonding test: Perform a one‑time visual inspection of centre fuel tank wiring and components as a general visual inspection per Note 1, which allows use of normally available lighting, removal of access panels and use of stands or ladders. Perform the one‑time electrical bonding test of centre fuel tank components in accordance with the SB (Requirement 1.a and 1.b).

5. Act on inspection/test findings immediately: If the visual inspection finds any discrepancy, either repair the discrepant component or replace it with a new or serviceable component as required by Requirement 2, and do so before further flight per Compliance item 2. If the electrical bonding test shows resistance above the limits in the service bulletin, rework the discrepant component per Requirement 3, and complete rework before further flight per Compliance item 3.

6. Perform the FQIS tasks: For aeroplanes listed in ASB 747‑28A2208 accomplish an insulation resistance test of the FQIS, a visual inspection of FQIS wiring and components for chafing or incorrect terminal block configuration, replace FQIS probes with new or serviceable components as detailed in Figure 5 of the ASB, and carry out system adjustment and operational test (Requirement 4). If any discrepancy is detected during these steps, perform corrective actions in accordance with the ASB, and complete them before further flight (Requirement 5 and Compliance item 5).

7. Install the flame arrestor where required: For aeroplanes having line positions 1-971 inclusive, install a flame arrestor in the inlet line of the electrical motor‑operated scavenge pump of the centre fuel tank, in accordance with ASB 747‑22A2210 dated 14 May 1998 (Requirement 6). This installation must be accomplished within 24 months after the effective date of the original issue of the Directive per Compliance item 6.

8. Verify use of authorised revisions and figures: Confirm that the SB/ASB revision used is one of the revisions specified in the AD. Where the AD references specific figures (for example Figure 5 of ASB 747‑28A2208), ensure the figure in the selected revision corresponds to what the AD authorises. Where earlier SB work exists, check Note 2 for permitted acceptance and exclusions.

9. Where necessary, apply AMOCs in accordance with recognised pathways: The AD references FAA AD 99‑08‑02 and specific FAA AMOCs (Note 5) and indicates that Amendments introduced alternate methods of compliance reflecting FAA AMOCs (Background). If an operator intends to use an AMOC as the means of compliance with Requirements 1-5, confirm the AMOC’s acceptance by CASA and retain documentary authorisation. The AD itself does not set out the procedural mechanism to obtain CASA acceptance of an AMOC.

10. Plan for logistics and parts: Requirement 4.c and Requirement 6 require replacement components and installation of the flame arrestor. Plan procurement of new or serviceable FQIS probes and flame arrestors as specified in the referenced ASBs and SBs to avoid delays that could extend grounding periods.

11. Document completion and maintain evidence: Although the AD does not prescribe a particular format for recordkeeping, operators should document inspections, tests, measurements, repairs and modifications performed in accordance with the SB/ASB and the AD, including dates and particulars of any parts replaced or reworked, to demonstrate compliance to CASA oversight or audits.

12. Treat "before further flight" repairs as immediate: If inspections or tests reveal discrepancies that require repair or rework, these must be completed before further flight. Incorporate contingency plans for potential grounding and for rapid parts acquisition and maintenance scheduling.

Following these steps, and ensuring that each action is performed "in accordance with" the applicable Boeing SB or ASB revision named in the AD, will align the operator’s technical activities with the Directive’s requirements.

The AD explicitly places itself under CASA’s statutory authority by stating it is issued under subregulation 39.1(1) of CASR 1998, thereby linking the technical obligations in the AD to the broader regulatory regime governing airworthiness and continuing airworthiness obligations in Australia (opening paragraph). The AD bases its technical findings and remedial tasks on FAA AD 99‑08‑02, thus reflecting an international regulatory interplay where CASA has adopted and adapted findings from the FAA’s rulemaking process (Background). The AD also references specific FAA AMOCs and states amendments introduced AMOCs reflecting FAA AMOCs for various Requirements (Note 5; Background), which shows cross‑jurisdictional recognition of alternate compliance approaches.

Within the aircraft maintenance and certification ecosystem, the AD’s requirements intersect with manufacturer service bulletins and alert service bulletins by making compliance contingent on performing tasks "in accordance with" specified SB and ASB revisions (Requirement 1, Requirement 4, Requirement 6). That creates a legalised technical linkage: the manufacturer documents provide the detailed procedural steps and measurement limits that implement the AD’s mandates. Note 2 creates a specific interaction between older and newer service documentation by permitting some prior actions under SB dated 27 June 1997 to be accepted as compliance for corresponding actions, but excluding certain inspections and tests described only in Revision 1 of the SB. Thus the AD moderates how earlier manufacturer‑issued actions are treated for regulatory compliance purposes.

The AD’s "before further flight" language creates an operational interplay with air operator obligations and certificate conditions: the AD prescribes remedial actions that must be completed prior to further flight, which operationally imposes groundings until remedial work is effected. Although the AD does not itself specify penalties for non‑compliance, the fact the Directive is issued under CASR authority implies that enforcement and penalties would be administered under CASR provisions; those enforcement mechanisms are outside the AD’s text.

Finally, because the AD references specific figures and part replacements in manufacturer ASBs, there is a contractual interaction with supply chains and maintenance agreements. Operators will rely on parts suppliers and maintenance providers to source the new or serviceable components specified in the ASBs. The AD does not allocate the cost, so the contractual arrangements between owners, operators and maintenance organisations will determine who pays for those parts and labour, but the regulatory obligation to effect the work remains with the operator.

(This section repeats the amendment history because the AD text sets it out explicitly, and it is important to restate the sequence as a discrete topic.)

The AD records a clear timeline of issuance and amendment:

• Original AD became effective on 17 June 1999. The Compliance section anchors several timeframes to this date.

• Amendment 1 became effective on 2 December 1999. The Background explains Amendment 1 clarified Requirement 4.c by replacing the terms "series 3" and "series 4" with a reference to a figure in the Boeing ASB. Amendment 1 also incorporated a definition of "visual inspection" as Note 1.

• Amendment 2 became effective on 6 September 2000. The Background states Amendment 2 introduced an alternate method of compliance (AMOC) for Requirements 4 and 5 reflecting a Federal Aviation Administration AMOC.

• The current Amendment 3 is signed by the CASA delegate James Coyne on 11 November 2004 and stated to become effective on 23 December 2004. The Background notes Amendment 3 introduces an alternate method of compliance for Requirements 1, 2 and 3 reflecting a Federal Aviation Administration AMOC.

The AD also records that it revokes AD/B747/201 Amdt 2 when the current AD takes effect. The Gazette notification date for the AD is recorded as 1 December 2004. Note 5 references FAA AD 99‑08‑02 R1 Amdt 39‑11215 and the FAA AMOCs AMOC 99‑140S‑177 (17 May 1999) and AMOC 99‑140S‑282 (11 August 1999), which were part of the reference material that informed the Amendments.

This amendment history shows iterative technical and procedural refinement, including clarification of technical references, the addition of inspection definitions, and the progressive recognition of FAA alternate methods of compliance across successive amendments.

The AD contains no record of litigation or court decisions. Its Background attributes the UK/US FAA AD as the originating technical source "based on Federal Aviation Administration AD 99‑08‑02, the issue of which was prompted by a design review and testing results obtained in support of an accident investigation." The AD does not otherwise identify or cite any judicial or administrative proceedings, appeals or legal challenges. There are no case citations, examples of enforcement proceedings, or appellate decisions referred to in the text.

Consequently, within the scope of the AD document provided, there is no litigation history to summarise. Any legal disputes concerning the AD’s validity, its interpretation, or enforcement would lie outside the contents of this instrument and are not recorded in the AD text.

(Repeated and expanded practical flagged items to ensure operability.)

• Deadline anchoring to original issue: Several compliance times are defined in relation to "the effective date of the original issue of this Directive." Operators must use the original issue effective date (17 June 1999) as the anchor for the "within 24 months" deadlines in Compliance items 1, 4 and 6. The current amendment effective date (23 December 2004) does not shift those particular timing anchors.

• Partial applicability for hardware change: Requirement 6 applies only to line positions 1-971 inclusive. Ensure fleet tracking distinguishes between line numbers inside and outside that range.

• Revisions and figure dependence: The AD permits alternative SB/ASB revisions but references specific figures in those documents for part identification, notably Figure 5 of ASB 747‑28A2208. Confirm that the figure in the revision you use corresponds to the item authorised by the AD and verify part numbers against the figure specified.

• Legacy work acceptance is limited: Actions carried out under SB 747‑28‑2205 dated 27 June 1997 are only acceptable for corresponding actions, and certain items such as inspection and testing of body fuel tank components described in Revision 1 are excluded (Note 2). Do not assume that any prior compliance clears all AD obligations.

• "Before further flight" obligations mean immediate remediation: If an inspection or test uncovers discrepancies, Requirements 2, 3 and 5 require repair, replacement or rework "before further flight". Be prepared for operational disruption and immediate maintenance scheduling if discrepancies are discovered.

• AMOC administrative uncertainty: The AD references FAA AMOCs and states amendments introduced AMOCs reflecting FAA AMOCs. The AD does not provide the administrative route to obtain CASA acceptance of an AMOC. Operators intending to rely on an AMOC must confirm CASA’s acceptance in Australia and retain documentary evidence.

• Definition of visual inspection: The AD’s Note 1 defines visual inspection narrowly as a general visual inspection. The note limits the scope of the inspection technique and sets expectations about lighting and access requirements. Ensure maintenance personnel implement inspections consistent with that definition.

• No explicit recordkeeping format: The AD does not prescribe how compliance is to be recorded. Ensure maintenance records and compliance evidence meet CASA's general recordkeeping expectations even though the AD does not specify them.

• Cross‑reference complexity: The AD incorporates content by reference to multiple SB/ASB revisions. Misalignment between the revision used for different tasks could create a compliance gap. Use the exact revisions named in the AD or an authorised AMOC.

Addressing these points in maintenance planning, parts procurement, and documentation will reduce the practical risk of non‑compliance or operational disruption.

(This section offers a practical compliance workflow summarised and expanded for operational planning, grounded strictly in the AD text.)

1. Identify applicable airframes: Confirm each aeroplane’s line number to determine AD applicability (Applicability). If the aircraft is within line numbers 1-1124, it falls within the AD. Separately identify whether the airframe’s line position is within 1-971 inclusive to determine whether Requirement 6 applies.

2. Source the correct SB/ASB revisions: Obtain SB 747‑28‑2205 Revision 1 dated 16 April 1998 or Revision 2 dated 17 May 1999 for centre fuel tank wiring tasks (Requirement 1). Obtain ASB 747‑28A2208 dated 14 May 1998 or Revision 1 dated 26 August 1999 for FQIS work (Requirement 4). Obtain ASB 747‑22A2210 dated 14 May 1998 for the flame arrestor installation (Requirement 6). Ensure the versions and figure numbers match those referenced.

3. Program inspections and tests against the AD schedule: The AD requires certain tasks "within 24 months after the effective date of the original issue of this Directive" and others "before further flight" if discrepancies are found (Compliance). Calculate the relevant deadlines using the original issue effective date (17 June 1999) for the "24 months" windows, and plan maintenance slots accordingly.

4. Execute the visual inspection per Note 1: The AD defines visual inspection as a "general visual inspection" with specific environmental and access expectations. Inspectors should use normal lighting, remove access panels when required, and employ stands or ladders to reach inspection areas.

5. Perform the electrical bonding test and compare to SB limits: The AD requires a one‑time electrical bonding test of centre fuel tank components (Requirement 1.b). Measure resistance and compare to the limits specified in the SB; if measured resistance exceeds those limits, rework the discrepant component per the SB (Requirement 3).

6. Conduct FQIS tests and replace probes where required: For aeroplanes subject to Requirement 4, carry out the insulation resistance test, perform the visual inspection of FQIS wiring and components, replace FQIS probes as detailed in Figure 5 of the ASB, then carry out system adjustment and operational test. If discrepancies are found perform corrective actions in accordance with the ASB (Requirements 4 and 5).

7. Carry out repairs and replacements before further flight: If inspections or tests reveal discrepancies, the AD mandates repair, replacement, or rework before the aircraft may be flown again (Requirements 2, 3 and 5; Compliance). Plan for potential grounding and immediate access to technical resources.

8. Install flame arrestor where applicable: For aircraft with line positions 1-971 inclusive, install the flame arrestor in the inlet line of the electrical motor‑operated scavenge pump of the centre fuel tank in accordance with ASB 747‑22A2210, within the AD’s specified timeframe (Requirement 6; Compliance).

9. Where using an AMOC, secure documentary authority: The AD references FAA AMOCs and states amendments introduced AMOCs reflecting FAA AMOCs. If planning to use an AMOC as a compliance route, ensure the AMOC is accepted by the relevant authority and retain the written authorisation. The AD does not set out the domestic AMOC approval process.

10. Maintain records of all actions: The AD requires accomplishment "in accordance with" the named SB/ASB. Maintain records that document the inspection procedures used, test results, measured values compared to the bulletin limits, conditioning for any repairs or part replacements, part numbers used (as per figure references), and dates of completion to prove compliance in any oversight review, noting the AD itself does not specify a recordkeeping format.

11. Coordinate parts and technical resources in advance: Requirement 4.c and Requirement 6 require parts replacements or installations of hardware. Pre‑order required new or serviceable components specified in the figures and ensure maintenance staff are familiar with the SB/ASB procedures to reduce aircraft downtime.

12. Monitor for further CASA guidance: Given that the AD references FAA AMOCs and has undergone multiple amendments, operators should monitor CASA communications for any further amendments, AMOC authorisations or clarifying guidance that affect permitted compliance methods.

Following this workflow, and strictly using the service documents and revisions specified in the AD text, will implement the Directive’s technical obligations as set out by CASA in AD/B747/201 Amdt 3.