AD/B747/173 Amdt 1 - Fuel Boost and Override/Jettison Pumps

The AD operates through a small number of concrete regulatory concepts and linkages to manufacturer-issued technical data. Those concepts are: applicability, mandatory actions, measurement thresholds, terminating actions, temporal compliance points, and reliance on service documents.

Applicability: The AD applies to "All model 747 aeroplanes" (Applicability). The universality of applicability means the directive’s requirements are not limited by operator, registry, or individual configuration except where the AD itself provides configuration-based exceptions or terminating conditions (Requirement 1.a-c).

Mandatory actions and methods: The AD makes actions mandatory and prescribes their execution "in accordance with" specified Boeing Service Bulletins and cites Boeing Telexes for additional information (Requirement, Notes). The primary inspection method is a visual inspection (Requirement 1) followed, where appropriate, by an insulation resistance test (Requirement 2). The AD therefore delegates the procedural detail,exact inspection points, test set-up and pass/fail criteria beyond the numeric thresholds,to the Boeing service bulletin referenced.

Measurement thresholds: The AD sets numeric thresholds for insulation resistance measurements that determine the next action. A measured resistance less than or equal to 1 MΩ requires immediate replacement (Requirement 3). Measurements greater than 1 MΩ but less than 5 MΩ permit two options: repeat the visual inspection within 500 hours TIS or replace the pump and retest (Requirement 4). Measurements strictly greater than 5 MΩ permit continued operation without immediate replacement, but the AD still prescribes follow-on inspection intervals (Requirement 4).

Terminating actions: The AD explicitly creates limited "optional terminating actions" for the Requirement 1 repetitive visual inspections. Those terminating actions are precise: for older B747-100/200/300/400 series, installation of GFI protection plus MPD amendment to ensure GFI circuit testing at “C” maintenance check intervals (Requirement 1.a); for certain B747-400 line numbers, installation of specified Hydro-Aire pump part numbers (Requirement 1.b); or installation per a later Boeing Service Bulletin (747-28A2241) (Requirement 1.c). These are configuration- or modification-based terminations; they are not unilateral waivers and must meet the AD’s explicit conditions to stop repetitive visual inspections.

Temporal compliance: The AD sets temporal rules: the repetitive visual inspection schedule "remains unchanged" as initial inspection prior to 14 July 1997 and thereafter at intervals not exceeding 5000 hours TIS or 18 months (Compliance). Tests triggered by inspections generally must be completed "prior to further flight" (Compliance for Requirements 2, 3, 5), while the option to repeat the visual inspection after a 1-5 MΩ measurement may be exercised within 500 hours TIS (Compliance for Requirement 4.a).

Inter-agency and manufacturer cross-references: The AD references FAA AD 97-03-17 and certain FAA AMOC letters (Note 2) and incorporates Boeing SBs and Telexes as the operative technical standards. The AD therefore functions partly by binding operators to follow the technical content of those documents and by pointing to FAA material for related guidance or previous decisions.

Remedial focus: The Background states the AD responds to Boeing reports of fuel leaks at the boost and override/jettison fuel pumps and that the initial AD aimed to provide early detection of leaks to prevent fire risk in the pump vicinity. This amendment’s explicit purpose is to introduce optional terminating actions for the repetitive visual inspections (Background).

The AD is procedural and corrective: it does not set out penalties in the body beyond prescribing compliance timelines and methods, but it is issued under CAR 1998 subregulation 39.1(1), which the instrument says authorises the CASA delegate to require necessary action to correct an unsafe condition. The AD binds operators to tasks to detect, test, and replace pumps according to specified criteria and to adopt the optional terminating modifications if they wish to stop repetitive inspections.

The AD directly affects operators, maintainers and owners of Boeing 747 series aeroplanes registered or operating under the jurisdiction of the Civil Aviation Safety Authority or otherwise subject to CASA ADs. The Applicability clause states "All model 747 aeroplanes", so any operator responsible for airworthiness of a 747 must follow the AD’s requirements as written (Applicability). By specifying actions to be performed "in accordance with Boeing Service Bulletin 747-28A2194 Rev 1" and additional Boeing documentation, the AD also imposes obligations on maintenance personnel and organisations who must implement and certify compliance with those service instructions (Requirement).

Who pays: The AD’s mechanics assign operational and direct financial burdens to aeroplane operators and maintenance organisations. Required activities include initial and repetitive visual inspections at the intervals specified ("prior to 14 July 1997 and thereafter at intervals not exceeding 5000 hours TIS or 18 months, whichever occurs first") (Compliance). When inspections reveal problems, the AD requires insulation resistance testing immediately and replacement of pumps if test thresholds are breached (Requirements 2-5). Those replacements require procurement of "new or serviceable" pumps per SB 747-28A2194 Rev 1 (Requirements 3 and 5). Costs for labour, test equipment, parts, and any downtime accrue to the operator or its maintenance provider.

Who decides or certifies compliance: The text states the CASA delegate issued the AD under CAR 1998 subregulation 39.1(1) and that the AD requires actions "in accordance with the instructions set out in the requirement section" and at the times in the compliance section. The requirement to perform actions "in accordance with" the Boeing SB means that the mechanics and the maintenance organisation exercising work for the operator are expected to follow the SB’s Accomplishment Instructions. Delegated CASA authority sets the regulatory obligation; the maintenance organisation and certifying staff are responsible for executing and documenting compliance per the SBs (opening paragraph; Requirement).

Supply-chain actors: The AD names specific Hydro-Aire part numbers for certain terminating conditions (Requirement 1.b). Operators seeking to use that terminating action must verify pump part numbers and possibly procure those parts. The AD also references Boeing Service Bulletin 747-28A2241 as another route to terminating inspections (Requirement 1.c), which implicates the availability of the parts or modifications described by that bulletin.

Maintenance planning: For operators seeking to use the GFI terminating action, the AD requires amendment of Maintenance Planning Data (MPD) to ensure GFI circuits are tested at "C" check intervals (Requirement 1.a). That imposes a maintenance-planning task on the operator and may affect maintenance scheduling, resource allocation, and costs.

Third-party references: The AD cites FAA AD 97-03-17 and FAA AMOC letters (Note 2) and Boeing telexes (Requirement footnotes). Those documents are not reproduced in the AD text, but the AD’s reference to them means operators will need to review those documents to confirm the technical content and any accepted alternative methods of compliance noted there.

Indirectly affected parties: Spare parts suppliers (Hydro-Aire or distributors), training providers for maintenance staff, and engineers tasked with implementing MPD changes or GFI installations will be engaged. Insurance and operational planning may be affected because mandatory pre-flight and pre-return-to-service actions (for failed tests or discrepancies) can create schedule risk.

In summary, the AD assigns monitoring, testing and replacement obligations to operators and maintenance organisations, binds them to Boeing technical instructions for how to perform those tasks, and offers narrowly defined configuration-based modifications that, if implemented and documented (e.g. MPD amendment), will stop the repetitive visual inspection burden for eligible aeroplanes.

Key duties: The AD sets a small set of mandatory duties for operators and maintenance organisations.

• Perform an initial visual inspection of the fuel boost and override/jettison pumps’ wire terminal assembly, electrical connector and wire insulation in accordance with Boeing SB 747-28A2194 Revision 1 (Requirement 1). The duty is mandatory and targeted at the specific pump assemblies and wiring described.

• Where no discrepancy is found on visual inspection, perform an insulation resistance test of each fuel pump’s wiring per the Accomplishment Instructions of SB 747-28A2194 Rev 1 (Requirement 2). Note 1 clarifies that each insulation resistance test includes a continuity check of the pump ground wire, as indicated in the SB.

• Replace pumps with a new or serviceable unit when a test returns a resistance measurement less than or equal to 1 MΩ, and repeat the insulation resistance test thereafter (Requirement 3). Replace pumps when a discrepancy is noted in the visual inspection and then perform the insulation resistance test (Requirement 5).

• For measurements greater than 1 MΩ but less than 5 MΩ, either repeat the visual inspection (within 500 hours TIS) or replace the pump prior to further flight and repeat testing (Requirement 4).

• Follow the specified compliance timeframes: the visual inspection schedule remains as previously stated,initially "Prior to 14 July 1997 and thereafter at intervals not exceeding 5000 hours TIS or 18 months, whichever occurs first",and tests or replacements triggered by inspections must generally be completed "prior to further flight" (Compliance).

• Implement terminating actions if chosen and if specific conditions are met: install GFI protection and amend MPD to test GFI circuits at "C" checks; install specified Hydro-Aire pump P/Ns for certain B747-400 line numbers; or install pumps per SB 747-28A2241 (Requirement 1.a-c).

Rights and discretion: The AD is prescriptive about required actions and timeframes; it does not grant broad discretion to deviate from the steps unless otherwise permitted by alternate methods of compliance (AMOCs) or other approvals. The AD references FAA AMOC letters in Note 2, but the Australian text does not itself state alternative compliance paths; it requires actions "in accordance with" Boeing SBs unless one of the specified terminating actions is taken. The AD does not explicitly set out an Australian AMOC process within its text; it does, however, indicate conformity with FAA materials by reference (Note 2), which suggests that operators might consult those FAA materials for alternative methods, but the AD does not itself adopt or grant those AMOCs. The initial paragraph frames the delegate’s authority under CAR 1998 subregulation 39.1(1) to require necessary corrective action; that authority is the source of duty imposition.

Interaction with manufacturer documents: The key duty includes following the Boeing service bulletin instructions exactly as referenced. Those instructions govern how the inspections and tests are to be conducted, and they specify that continuity checks of ground wires are included in the resistance test (Note 1). The AD therefore places an operational duty on maintenance staff to follow the SB's procedures, including any specified tools, test voltages, and test sequences the SB mandates.

Documentation and certification: The AD requires actions "in accordance with" the Boeing SBs and specifies timing "prior to further flight" for many triggers. That implies that aircraft cannot return to service until the inspections/tests and any required replacements are completed. The AD text does not itself set out record-keeping obligations or certification statements, but standard maintenance practice and the SBs referenced will contain the steps to certify completion. The AD binds operators to complete the tasks before returning the aircraft to service on safety grounds.

Limitation: Termination of the repetitive inspection obligation is conditional and narrowly defined; only when the AD’s specific conditions are satisfied (1.a-c) do operators obtain relief from repetitive visual inspections. The AD does not provide broader waivers or indefinite approvals beyond those specified.

In sum, the AD creates firm duties to inspect, test and replace fuel pumps under particular numeric criteria and allows limited, clearly stipulated routes to end the repetitive inspection obligation, subject to the precise configuration or maintenance-planning changes specified.

The AD text itself does not include a penalty schedule or administrative sanctions. It is issued under the authority of the CASA delegate pursuant to CAR 1998 subregulation 39.1(1), as stated in the issuing paragraph, which is the regulatory source authorising the delegate to require actions "necessary to correct the unsafe condition" (opening paragraph). The AD prescribes mandatory corrective actions and compliance timeframes; enforcement mechanisms and penalties for non-compliance are not described within this AD document.

Practical enforcement mechanism: Although this AD does not spell out penalties, the instrument’s mandatory nature and the phrase "requires that the action set out in the requirement section... be taken" make it an obligatory regulatory instrument. Compliance must be completed at the times the AD states (Compliance). Operators that fail to comply with a CASA AD would, as a matter of regulatory practice, be exposed to enforcement pursuant to the broader Civil Aviation Regulations and the criminal or administrative provisions that give CASA enforcement powers; however, those specific sanctions are not listed in the AD itself and thus cannot be stated as part of this AD’s text.

Operational enforcement consequences implicit in the AD: The AD requires certain actions "prior to further flight" when discrepancies or threshold breaches are found (Compliance for Requirements 2, 3 and 5). That phrasing effectively prohibits continued operation of an affected aircraft until the corrective action and retesting have been accomplished; in practice, that creates an operational enforcement condition because an aircraft may not legally be returned to service until required maintenance and testing are complete and the operator has satisfied the AD’s requirements. The AD thereby imposes an operational stop-gap where an aircraft with a pump below the specified resistance threshold cannot continue to fly "prior to further flight" without completing the remedial tasks.

References to FAA documents: Note 2 references FAA AD 97-03-17 and several FAA AMOC letters. Those references provide context for accepted means of compliance in the FAA system and may be informative to CASA or operators when assessing equivalence, but the AD does not itself adopt or implement those FAA AMOCs in the text; it only refers to them.

Delegated authority and signature: The AD is signed by the CASA delegate (Eugene Paul Holzapfel) and dated 28 June 2002 (signature block). That signature is the instrument’s formal validation under CASA administrative process.

Effective date and notification: The AD becomes effective on 8 August 2002 (Compliance), and it was notified in the Commonwealth of Australia Gazette on 17 July 2002 (final line). Those dates mark when the AD’s requirements become legally operative for affected operators.

In summary, the AD prescribes mandatory corrective and preventive maintenance obligations and timeframes. The AD text does not itself spell out penalties, but it conditions return-to-service on completion of required work and is issued under CASA’s regulatory authority, which in the regulatory system provides enforcement mechanisms external to the AD text.

The AD explicitly situates itself within the Civil Aviation safety regulatory framework by stating it is issued under subregulation 39.1(1) of CAR 1998 (opening paragraph). That clause is the legal authority the CASA delegate cites for revoking the prior AD and issuing this AD. The AD therefore functions as a regulatory instrument implementing CAR authorisation; it imposes obligations on operators that are part of the broader regulatory duties found in aviation safety law. The AD text itself does not reproduce CAR 1998 or provide detail about appeals, enforcement powers beyond compliance, or administrative procedures; it simply notes the delegate’s authority under that subregulation.

Manufacturer documentation and foreign regulator material: The AD mandates that required actions be carried out "in accordance with Boeing Service Bulletin 747-28A2194 Rev 1 dated 18 January 1996" and references Boeing Telexes (Requirement). Those Boeing documents are not law in themselves but become effectively mandatory for compliance with the AD. Operators must therefore align their maintenance actions with the SB and telexes to meet the AD’s legal obligation. This creates an interaction where non-legal technical documents gain regulatory effect by being incorporated by reference in the AD.

The AD also refers to FAA AD 97-03-17 Amdt 39-9922 and FAA AMOC letters (Note 2). The AD does not incorporate those FAA documents into Australian law directly but references them as related documents. Operators and maintainers will likely consult FAA materials for technical clarification or methods of compliance accepted by the FAA; however, the AD’s text does not equate FAA AMOCs to automatic acceptance in Australia. The AD’s earlier paragraph establishes that the CASA delegate may require action considered necessary; whether an FAA AMOC constitutes an accepted equivalent method within CASA jurisdiction is not stated in the AD itself.

Interaction with maintenance planning and organisational requirements: The AD requires, as an optional terminating action for some aeroplanes, that "Maintenance Planning Data (MPD) documentation is amended to ensure GFI circuits are tested at 'C' maintenance check intervals" (Requirement 1.a). MPD is an element of an operator’s maintenance planning and approved maintenance programme. The AD therefore directly affects an operator’s maintenance planning process, requiring amendment of MPD for the terminating action to apply. That creates an interface between the AD and an operator’s regulatory obligations for approved maintenance programs,MPD amendments will need to be prepared, approved, and implemented in line with existing regulatory processes for maintenance programme changes, although the AD does not specify those steps.

Return-to-service and certification: The AD requires certain tests and replacements to be completed "prior to further flight" (Compliance). Achieving compliance will interact with the operator’s return-to-service certification processes and the regulatory requirement to ensure airworthiness before flight. The AD acts as a condition that must be satisfied before the aircraft may fly if testing or inspections detect non-compliance.

Superseding and revocation: The opening paragraph states that the CASA delegate "revokes Airworthiness Directive (AD) AD/B747/173 and issues the following AD", so this Amendment replaces the prior AD. The AD therefore supersedes the earlier instrument for the matters it addresses. The text also states the original AD became effective on 27 March 1997 (Background), so this amendment revises and adds to the prior directive, particularly by introducing terminating actions.

In sum, the AD interacts with CAR 1998 (the legal authority); with Boeing SBs and telexes by making them the operative technical instructions; with maintenance planning (MPD) where GFI-term conditions are chosen; and references FAA materials as contextual or potentially informative documents. The AD itself does not incorporate FAA AMOCs as automatic Australian approval, nor does it detail administrative processes for MPD amendment, enforcement procedures, or appeals; resolving those operational or legal details requires reference to CAR 1998 and other regulatory instruments outside the AD text.

The AD text contains its own succinct amendment history and references to predecessor documents.

• Original AD: The Background notes "The original issue of this Airworthiness Directive became effective on 27 March 1997." That original issue followed Boeing advice reporting fuel leaks at the boost and override/jettison fuel pumps, and its purpose was to provide early detection of fuel leaks to reduce the likelihood of fire near the affected pumps (Background).

• Revocation and reissue: The opening paragraph states that the CASA delegate "revokes Airworthiness Directive (AD) AD/B747/173 and issues the following AD." The instrument issued here is titled AD/B747/173 Amdt 1 and dated 8/2002 (title block). The Amendment revises the original AD by introducing optional terminating actions for the Requirement 1 repetitive inspections, a change explicitly noted in the Background ("This Amendment introduces optional terminating actions for the Requirement 1 repetitive inspections").

• Effective dates: The Amendment becomes effective on 8 August 2002 (Compliance). The AD also indicates it was notified in the Commonwealth of Australia Gazette on 17 July 2002 (final sentence). The delegate signed the AD on 28 June 2002 (signature block), indicating the administrative timeline between signature, gazettal notification, and effective date.

• Technical updates and cross-references: The Requirement section incorporates Boeing Service Bulletin 747-28A2194 Revision 1 (dated 18 January 1996) as the primary procedural document. The Amendment adds cross-references to Boeing Telex M-7200-02-00852 dated 31 May 2002 and Boeing Telex M7200-02-00939 dated 20 June 2002 for the terminating action conditions (Requirement 1.a-c). The Amendment also references Boeing Service Bulletin 747-28A2241 dated 11 June 2002 as an alternative terminating route (Requirement 1.c). Note 2 also references FAA AD 97-03-17 Amdt 39-9922 and FAA AMOC letters 140S-02-156, 130S-02-253 and 140S-02-191.

• Continuity of inspection interval: The Compliance section expressly states that "For Requirement 1 - Remains unchanged as 'Prior to 14 July 1997 and thereafter at intervals not exceeding 5000 hours time in service (TIS) or 18 months, whichever occurs first'." This shows the Amendment retains the initial inspection cadence from the original AD while adding the new terminating-action options.

• Specifics of changes: The Amendment’s operative change is narrowly framed: it introduces optional terminating actions; it does not otherwise change the initial inspection steps, test thresholds, or the immediacy of certain remedial actions. The AD sets out Requirements 1-5 in the same structure as the original but adds the items 1.a-c as conditions under which repetitive visual inspections can be terminated.

No further amendments beyond "Amdt 1" are recorded in the text. The AD does not set out future review or sunset provisions; it simply replaces the prior instrument and becomes effective on the date specified.

For those tracking regulatory history, the text provides the essential milestones: original effectiveness 27 March 1997, amendment signed 28 June 2002, Gazette notification 17 July 2002, and Amendment effective 8 August 2002. It also documents the Boeing and FAA documents that were relevant to the Amendment’s changes.

The AD text contains no litigation history, case citations, court challenges, or administrative appeals material. The document does not reference any legal proceedings, judicial review, or contested enforcement actions relating to AD/B747/173 or this Amendment. Note 2 references FAA AD 97-03-17 and FAA AMOC letters, but those are regulatory and administrative documents from the FAA system; the AD does not mention any litigation arising from those FAA instruments.

What the AD does provide is the administrative provenance of the Amendment: it states the CASA delegate revoked the prior AD and issued this Amendment under authority granted by CAR 1998 subregulation 39.1(1) (opening paragraph), and it records the delegate’s signature and dates (signature block). It also records the gazettal date for notification (17 July 2002) and the effective date (8 August 2002) (Compliance). Those administrative markers are the only recorded procedural history inside the AD.

Absent external documents, the AD does not disclose whether any operator sought an alternative method of compliance, lodged an objection or challenge, or pursued a legal appeal against the Amendment. The AD’s Note 2 points to FAA AMOC letters, which are FAA determinations of alternative methods of compliance in the FAA system; those letters are referenced for information but the AD does not state whether any FAA AMOC has been accepted as an Australian equivalent or whether any Australian AMOC process has been invoked. The AD text itself contains no record of requests for exemptions, waivers or AMOC submissions to CASA, nor any judicial or administrative outcomes.

For practitioners, therefore, the AD provides no Australian litigation or dispute history to consult; any examination of litigation or contested enforcement would require review of external sources beyond this AD text, such as CASA enforcement records, FAA AMOC correspondence, or operator records, none of which are included in the AD itself.

Several operational and interpretive pitfalls are built into the AD’s language and structure that operators and maintainers should note carefully.

1. Timing language retained from the original AD: The Compliance section says "For Requirement 1 - Remains unchanged as 'Prior to 14 July 1997 and thereafter at intervals not exceeding 5000 hours time in service (TIS) or 18 months, whichever occurs first'." The phrasing refers to a date in the past relative to the 2002 Amendment. Practitioners must interpret this as preserving the original inspection cadence (initial inspection before a past date for compliance records, then thereafter at the stated interval) rather than treating the AD as newly triggering a "first" inspection only upon Amendment. In practical terms, operators should ensure their inspection schedules remain at no greater than 5000 hours TIS or 18 months (Compliance). The text does not explain transitional recordkeeping for initial inspections that would have been due prior to 14 July 1997, so operators should check their records to demonstrate compliance.

2. "Prior to further flight" is an immediate return-to-service barrier: For Requirements 2, 3 and 5 the AD requires actions "Prior to further flight immediately following" the inspection or test. That wording means that if a discrepancy or failing test occurs, the aircraft cannot return to flight until replacement and re-testing are completed and done in accordance with the SB. That can result in immediate operational disruption, spare-part procurement needs, and scheduling impacts.

3. Numeric thresholds and test procedure dependency on the SB: The AD sets insulation resistance numerical thresholds (≤1 MΩ; between 1 MΩ and 5 MΩ; >5 MΩ) (Requirements 3-4). However, the AD relies on the Boeing SB for test methodology and for the inclusion of the ground wire continuity check (Note 1). Practitioners need to ensure their test equipment settings and procedures align with the SB’s Accomplishment Instructions; differences in test voltage, duration, or grounding technique can change measured resistances and therefore the required remedial action. The AD does not list the SB’s test voltage or methodology; it mandates use of the SB.

4. "New or serviceable" pump terminology: Requirements 3 and 5 require replacement with a "new or serviceable" pump "in accordance SB 747-28A2194 Rev 1". The AD does not define "serviceable" in the text; operators should consult the referenced SB for criteria that qualify a pump as serviceable, and they should ensure their supply chain provides parts that meet the SB’s acceptability criteria.

5. Narrow scope of optional terminating actions: The new terminating actions are narrowly written and conditional. For example, Requirement 1.b applies only to B747-400 series aeroplanes with line number 1294 or greater with specific Hydro-Aire pump P/Ns. An operator assuming that installing the specified Hydro-Aire pumps on any B747-400 would terminate inspections risks non-compliance unless the line number condition and other requirements are met. Similarly, for GFI installation in Requirement 1.a, the MPD must be amended to ensure GFI circuits are tested at "C" maintenance check intervals; simply installing GFI without MPD amendment will not meet the AD’s condition as written.

6. Cross-referenced telexes and SBs are not reproduced: The AD references Boeing Telex M-7200-02-00852 and M7200-02-00939 and Service Bulletin 747-28A2241 for the terminating actions, and FAA materials in Note 2. The text of those telexes, the SB 747-28A2241, and the FAA documents are not included in the AD itself. Operators must obtain and review those documents to verify applicability and to implement terminating actions correctly.

7. Potential ambiguity about acceptance of FAA AMOCs: Note 2 cites FAA AMOC letters by number. The AD does not state that those AMOCs are accepted in Australia. Operators should not assume that FAA AMOCs automatically provide relief from this AD without CASA confirmation, because the AD text does not adopt them by reference as Australian approvals.

8. Record and certification implications not stated: The AD requires actions that affect return-to-service, yet it does not itself spell out the recordkeeping or certification wording for approving release to service after compliance. Operators must ensure maintenance entries and compliance documentation meet CASA requirements and any SB-prescribed completion records, even though those administrative details are not described in the AD.

9. Differences among 747 variants: The AD applies to "All model 747 aeroplanes" but several of the terminating-action conditions are model- and line-number-specific (Requirement 1.a-c). Operators must be careful to check their aeroplane model, line number, pump part numbers, and MPD status before assuming that a terminating action applies.

10. Repetitive inspection termination is optional and conditional: Repetitive visual inspections "may be terminated if any of the conditions specified in Requirement 1.a., 1.b. or 1.c. are met" (Compliance). Operators seeking operational relief must implement the precise modifications and documentation changes required; simply asserting a modification was made without verifying the AD’s exact conditions risks non-compliance.

These "gotchas" are matters of precise compliance interpretation and operational implementation. The AD’s brevity places a premium on consulting the referenced service bulletins, telexes, and maintenance planning data to ensure full conformity.

Compliance with this AD requires following the stepwise requirements and timelines the AD sets out and performing the work in accordance with the Boeing Service Bulletins and telexes referenced. Below is a practical, source-grounded checklist and sequence strictly reflecting the AD text.

1. Confirm applicability: Verify that the aeroplane is a Boeing 747 model. The AD applies to "All model 747 aeroplanes" (Applicability).

2. Schedule and record the recurring visual inspections: Ensure that the initial and repetitive visual inspections of the fuel boost and override/jettison pump wire terminal assembly, electrical connector and wire insulation are scheduled "Prior to 14 July 1997 and thereafter at intervals not exceeding 5000 hours TIS or 18 months, whichever occurs first" (Compliance for Requirement 1). For ongoing compliance, maintain an inspection schedule no longer than 5000 hours TIS or 18 months.

3. Obtain Boeing technical documents: Acquire Boeing Service Bulletin 747-28A2194 Revision 1 dated 18 January 1996 and the other referenced documents (Boeing Telexes M-7200-02-00852 and M7200-02-00939, and SB 747-28A2241 dated 11 June 2002 if considering terminating actions). The AD requires actions "in accordance with" the SBs (Requirement).

4. Perform the visual inspection per SB: Conduct the initial visual inspection of the fuel pump assemblies and wiring per the Accomplishment Instructions of SB 747-28A2194 Rev 1 (Requirement 1). Document any discrepancies such as fuel leak, heat discolouration or damage.

5. If no discrepancies on visual inspection, perform insulation resistance test immediately: The AD mandates an insulation resistance test of each fuel pump’s wiring per SB instructions "Prior to further flight immediately following the Requirement 1 visual inspection" (Requirement 2; Compliance). Ensure the insulation test includes a continuity check of the pump ground wire as the SB requires (Note 1).

6. Interpret test results against AD thresholds:

   • If any resistance measurement is ≤ 1 MΩ: Replace the fuel pump with a new or serviceable pump in accordance with SB 747-28A2194 Rev 1, then repeat the insulation resistance test prior to further flight (Requirement 3; Compliance).
   • If all resistance measurements are > 1 MΩ but < 5 MΩ: Either (a) repeat the Requirement 1 visual inspection within 500 hours TIS after the insulation resistance test (Requirement 4.a; Compliance), or (b) replace the fuel pump with a new or serviceable pump in accordance with SB 747-28A2194 Rev 1 and repeat the insulation resistance test prior to further flight (Requirement 4.b; Compliance).
   • If any discrepancy was noted during the Requirement 1 visual inspection: Replace the pump with a new or serviceable unit per SB 747-28A2194 Rev 1, and perform the Requirement 2 insulation resistance test prior to further flight (Requirement 5; Compliance).

7. Replacement parts and serviceability: When replacement is required, ensure pumps are "new or serviceable" and procured or overhauled in accordance with SB 747-28A2194 Rev 1. Consult the SB for part eligibility and serviceable condition criteria.

8. Return to service: For any action that is mandated "prior to further flight", do not release the aeroplane to flight until the required replacement/retest or visual recheck has been completed and documented in accordance with the SB and your maintenance-release procedures (Compliance for Requirements 2, 3, 5).

9. Consider optional terminating actions if seeking relief from repetitive visual inspections:

   • For B747-100, -200, -300 and -400 series: install fuel pumps with GFI protection and amend MPD documentation to ensure GFI circuits are tested at "C" maintenance check intervals. Confirm the telex Boeing M-7200-02-00852 for precise instructions and MPD amendment details (Requirement 1.a).
   • For B747-400 series with line number 1294 or greater: install Hydro-Aire fuel boost pumps P/N 60B89004-15 and override pumps P/N 60B92603-26 (Requirement 1.b). Confirm line number eligibility and the Boeing Telex referenced.
   • For B747-100, -200, -300 and -400 series: install Hydro-Aire pumps in accordance with Boeing Service Bulletin 747-28A2241 dated 11 June 2002 (Requirement 1.c; see Boeing Telex M7200-02-00939). Only after meeting the stated conditions may repetitive visual inspections be terminated (Compliance).

10. Update maintenance planning and MPD where applicable: If relying on GFI installation to terminate inspections, amend MPD documentation to ensure GFI circuit testing at "C" check intervals, as the AD requires (Requirement 1.a). Ensure any MPD amendment is performed consistent with regulatory requirements for maintenance programme changes (the AD requires the MPD change as a condition).

11. Retain and reference supporting documents: The AD references FAA AD 97-03-17 Amdt 39-9922 and FAA AMOC letters (Note 2). Although the AD does not adopt those FAA AMOCs as Australian approvals, review the FAA documents for technical context or to understand previously accepted means of compliance; obtain Boeing telexes to confirm specific technical instructions and applicability.

12. Plan logistics and spares: Given that replacements are mandatory in some cases and that return-to-service is prohibited until remedial actions are completed, plan for availability of spare pumps and trained maintenance personnel. Ensure test equipment meets the SB-prescribed values and that personnel performing insulation resistance and continuity checks are trained to the SB method.

13. Document compliance and maintain records: The AD requires actions "in accordance with" Boeing SB instructions; the SB will contain the required accomplishment records. Ensure maintenance records reflect the inspections, tests, replacements and any MPD amendments used to terminate repetitive inspections. Although the AD text does not explicitly set out recordkeeping rules, regulatory practice requires appropriate maintenance entries to show compliance before returning the aircraft to service.

14. Keep awareness of updates: The AD supersedes the prior AD and is effective from the date specified. Operators should monitor for further AD amendments, Boeing service bulletin revisions, or CASA guidance that may modify acceptance of FAA AMOCs or change terminating action criteria.

By following the AD’s stepwise requirements, using the Boeing service bulletin as the operational procedure manual, and adhering to the stated compliance timeframes, operators can meet the directive’s obligations. The AD provides no alternative compliance procedure within its text beyond the optional terminating actions; any alternative method would require engagement with CASA and relevant documented approvals outside the AD itself.