AD/B747/307 - Integrated Drive Generator Power Feeder Cables

The AD rests on a small set of operational concepts, expressed in the Requirement and Background sections and operationalised by reference to Boeing service documents.

Inspections as a regulatory device

• The AD mandates repeated general visual inspections as an immediate mitigation. The AD defines “general visual inspection” in Note 1: a non-invasive sight check from touching distance using normal lighting, potentially requiring mirror access, removal or opening of access panels and the use of stands, ladders or platforms. The definition limits the inspection to detection of obvious damage, failure or irregularity and is not a detailed or structural examination.
• Two inspection streams are specified: forward strut conduit and IDG power feeder cable inspections (Requirement 1) and outboard strut aft-section inspections checking power feeder cables and adjacent hydraulic lines for chafing (Requirement 3). The AD prescribes the exact Boeing SB/ASB accomplishment instructions for how to perform and record these inspections (SB 747-24A2240 Rev 1; ASB 747-24A2247).

Repairs and immediate grounding risk

• Any damage found in the inspections must be repaired in accordance with the indicated Boeing documents and, where damage is found, the AD requires those repairs to be carried out before further flight (Requirements 2 and 4). The “before further flight” requirement creates an immediate operational constraint: a damaged finding, however small, grounds the aircraft until authorised repair is completed.

Terminating modifications

• The AD sets out two terminating modification paths: the conduit removal, shield/bracket installation and hydraulic line replacement (Requirements 5 and 6) stops the Requirement 1 repetitive inspections; replacement of the wiring and hydraulic tubing support bracket (Requirement 7) stops the Requirement 3 repetitive inspections. Each terminating action is required “within 48 months after the effective date of this Directive.” The AD explicitly states that accomplishing the specified Requirements terminates the related repetitive inspections.

Prescriptive reference to OEM instructions

• The AD does not provide repair or modification engineering detail in the text itself. Instead, it prescribes compliance “in accordance with the Accomplishment Instructions” of specific Boeing SBs/ASBs and identifies the exact revision and dates where applicable. The AD therefore requires operators to implement the methods and limits contained in those Boeing documents.

Timing and monitoring

• Initial compliance timing is 90 days from the AD effective date for the first inspection, and thereafter inspections are required at intervals not to exceed 10,000 hours TIS unless earlier terminated by the specified modification actions. The terminating actions have a 48-month outer window.

Safety rationale as stated

• The Background section sets out the safety risk: damage and arcing of the conduit and IDG power feeder cables could cause a fire in the engine strut; damage to adjacent hydraulic lines could lead to reduced controllability of the aeroplane. The AD therefore aims to detect and correct conduit, cable and hydraulic-line damage and to provide permanent structural/support changes that remove the need for continued inspection.

Cross-jurisdictional reference

• The AD explicitly refers to FAA AD 2004-11-03 Amdt 39-13648, indicating alignment with the United States Federal Aviation Administration’s corresponding directive, and ties compliance to Boeing service documents, which are manufacturer-originated technical instructions.

Legal authority

• The AD is issued under subregulation 39.1(1) of CASR 1998, with the CASA delegate's signature. It states that the delegate requires the action necessary to correct the unsafe condition to be taken “in relation to the aircraft” under the circumstances set out and at times specified in the compliance section.

The AD sets a narrow applicability and therefore affects a defined group of stakeholders.

Aircraft operators

• The AD applies to Boeing 747-400 and 747-400F series aeroplanes having line numbers 696 through 1310 inclusive and equipped with Rolls-Royce engines. Operators of those specific aeroplanes bear the direct compliance burden. Aircraft outside this line-number range or equipped with other engine types are not within the stated applicability and therefore are not covered by this AD as written.

Maintenance organisations and MROs

• Maintenance organisations that service the affected aeroplanes are responsible for carrying out the inspections, repairs and terminating modifications in accordance with the cited Boeing SB/ASB accomplishment instructions. The AD will require those organisations to allocate labour hours, parts and facilities (stands, ladders, access panels) and to follow Boeing procedures.

Boeing, parts suppliers and OEM service providers

• Boeing is indirectly involved because compliance is to be performed “in accordance with” Boeing SBs/ASBs. The AD references specific Boeing documents by number, revision and date, which makes Boeing’s recommended methods the compliance baseline. Suppliers of the new shield/bracket assemblies, hydraulic lines and wiring/hydraulic support brackets will be parties that sell the parts necessary to accomplish the terminating actions.

Regulators and inspectors

• The CASA delegate and responsible CASA inspectors exercise regulatory authority to issue the AD and verify compliance. The AD itself does not set out enforcement steps, but it was issued under CASR subregulation 39.1(1), so CASA is the issuing regulator and delegates monitor compliance under CASR.

Operators’ commercial stakeholders

• Airline planning, scheduling, finance and safety functions are affected. The AD’s inspections and the “before further flight” repairs may remove aircraft from service unexpectedly or for scheduled downtime. Operators will choose whether to incur the one-off capital and labour expense of the terminating modifications (which stop the recurring inspection burden) or to continue periodic inspections.

Flight operations and residual safety

• Pilots and flight operations staff are affected indirectly because the AD creates operational constraints: aircraft with damage identified at the inspections must be repaired before further flight. That constraint interacts with dispatch planning and safe flight rules.

International operations

• The AD cross-references FAA AD 2004-11-03. Operators that fly internationally between jurisdictions where the FAA or CASA oversight applies will need to maintain compliance with both authorities’ directives; this cross-reference suggests harmonised regulatory expectations for the underlying unsafe condition.

Who pays

• The AD places the cost of inspections, repairs, parts and downtime on the operators and their chosen maintenance providers. The AD does not indicate government funding or cost-sharing. Parts and labour for the terminating modifications are expected to be paid by the operator unless otherwise arranged with lessors, manufacturers or insurers.

Who decides

• Regulatory decision-making was exercised by the CASA delegate who issued the AD under subregulation 39.1(1) of CASR 1998. Operational decisions,scheduling inspections, selecting repair or terminating modification timing, and contracting MROs,are made by operators and their maintenance organisations, within the deadlines and prescriptive methods the AD specifies.

The AD places clear, prescriptive duties on affected operators and maintenance organisations, and identifies the methods (Boeing SB/ASB accomplishment instructions) to be followed. The AD also conveys certain rights by implication, principally the option to choose between continuing inspections or undertaking terminating modifications.

Primary duties imposed by the AD

• Perform initial general visual inspections for damage or arcing of the IDG power feeder cables and the cable conduit in the forward section of all four engine struts, as required by Requirement 1 and in accordance with Boeing SB 747-24A2240 Revision 1. The initial inspection window is within 90 days after the effective date of the AD and must be repeated at intervals not to exceed 10,000 hours TIS until Requirements 5 and 6 are accomplished (Compliance paragraph for Requirement 1).
• Repair any damage detected by the Requirement 1 inspection in accordance with SB 747-24A2240 Revision 1, and do so before further flight following the inspection (Requirements 2; Compliance for Requirement 2: before further flight).
• Perform initial general visual inspections for chafing and arcing damage of the power feeder cables and hydraulic lines on each outboard strut aft of the block clamp in accordance with Boeing Alert Service Bulletin 747-24A2247 (Requirement 3). The initial inspection window is within 90 days of the AD effective date and repeats at intervals not to exceed 10,000 hours TIS until Requirement 7 is accomplished (Compliance paragraph for Requirement 3).
• Repair any chafing or arcing damage found during Requirement 3 inspections in accordance with ASB 747-24A2247 and before further flight (Requirements 4 and Compliance for Requirement 4).
• Within 48 months of the AD effective date, remove the conduit, install the new shield/bracket assembly and replace two hydraulic lines with two new hydraulic lines in each engine strut as specified in SB 747-24A2242 Revision 1 (Requirement 5; Compliance for Requirement 5: within 48 months). After replacement, pressurise the hydraulic system and examine for leaks, repairing leaks as necessary prior to further flight (Requirement 6; Compliance for Requirement 6: before further flight). Completing Requirements 5 and 6 terminates the Requirement 1 repetitive inspections.
• Within 48 months of the AD effective date, replace the wiring and hydraulic tubing support bracket per ASB 747-24A2243 (Requirement 7; Compliance for Requirement 7: within 48 months). Completing Requirement 7 terminates the Requirement 3 repetitive inspections.

Procedural and documentary duties

• The AD requires compliance “in accordance with the Accomplishment Instructions” of the specified Boeing SBs and ASBs. Operators therefore have a duty to obtain and follow the specified Boeing documentation in the stated revision and date. The AD’s use of manufacturer accomplishment instructions converts those documents into the regulatory compliance template for the AD.

Inspection standard and access

• The AD includes a formal note (Note 1) defining “general visual inspection.” The note establishes the standard for what constitutes adequate inspection access and lighting, and prescribes that stands, ladders or platforms might be required to gain proximity. Removal or opening of access panels or doors is permitted to achieve the inspection.

Timing duties that constrain operations

• The AD’s “before further flight” repair requirements (Requirements 2 and 4) mean that any aircraft found with damage at the inspection must be grounded until the required repair is completed in accordance with the Boeing instructions. That is a material operational constraint that must be managed by operators in their maintenance and flight scheduling.

Rights and choices preserved by the AD

• The AD gives operators a decision point: either continue the repetitive inspections at 10,000-hour intervals or elect to accomplish the terminating modifications (Requirements 5-7) within 48 months. Completion of the terminating actions removes the repetitive inspection obligation. That creates a trade-off between periodic inspection costs and one-time modification costs. The AD does not mandate immediate performance of terminating modifications, only that they be completed within 48 months.

Limits of the AD,what it does not impose

• The AD does not itself specify repair engineering details; those are delegated to the Boeing SB/ASB accomplishment instructions. The AD does not specify penalties or enforcement mechanisms in its text; it identifies CASA’s authority under CASR subregulation 39.1(1) as the issuing authority.

Cross-reference duty

• The AD notes FAA AD 2004-11-03 Amdt 39-13648 (Note 2). Operators who operate under multiple jurisdictions should treat that cross-reference as a cue to confirm parallel FAA obligations, but the AD itself binds the operators within the Australian regulatory framework for the aeroplanes to which it applies.

The AD text specifies the issuing authority and the legal basis but does not set out penalty amounts or procedural enforcement steps within its own text. The AD states that it is issued under subregulation 39.1(1) of CASR 1998 and that the CASA delegate whose signature appears has issued the AD. The AD becomes effective on 5 August 2004 and was notified in the Commonwealth Gazette on 14 July 2004.

Legal force and implied enforcement

• The AD is issued under CASR subregulation 39.1(1), which is invoked as the statutory authority for requiring corrective action to address an unsafe condition. The AD therefore operates as a regulatory instrument with binding effect on the aircraft and operators within its applicability. The AD’s mandatory language,"The AD requires that the action set out in the requirement section ... be taken",creates enforceable compliance obligations for affected operators.

What the AD does not say

• The AD text does not specify penalties, infringement notices, or particular enforcement processes or sanctions for non-compliance. The AD likewise does not include a compliance audit protocol, reporting obligations to CASA beyond the requirement to do the work “in accordance with” Boeing instructions, or a form to be returned to CASA. The AD does not specify post-action inspection verification steps to be performed by CASA or its delegate.

Practical enforcement implication

• Because the AD is issued under CASR and notified in the Commonwealth Gazette, compliance failure will be assessed against the regulatory requirement framework in CASR and CASA enforcement policies and practices. The AD itself contains explicit “before further flight” requirements that, if not complied with, would leave an aircraft in a state inconsistent with the AD and so inconsistent with airworthiness requirements under CASR; CASA’s enforcement response would be governed by CASR and CASA’s standard enforcement processes rather than by content in this AD.

Cross-reference to FAA AD

• The AD refers to FAA AD 2004-11-03 (Note 2). Where operators are subject to both CASA and FAA jurisdiction, failure to comply with either regulator’s AD may expose the operator to enforcement by the relevant authority. The AD does not set out coordinated enforcement processes between CASA and FAA; the cross-reference is informational and indicates correspondence between the directives.

Summary

• The AD imposes binding requirements under CASR subregulation 39.1(1), with mandatory inspection, repair and modification deadlines and “before further flight” constraints; however, it does not contain standalone penalty provisions or a step-by-step enforcement protocol in its own text. Enforcement and penalties, where invoked, would be applied pursuant to CASR and CASA’s regulatory enforcement mechanisms.

This AD sits within the Australian aviation regulatory framework and cross-references a related FAA AD and manufacturer service publications. The AD explicitly states that it is issued under subregulation 39.1(1) of CASR 1998. That is the linking legal authority connecting the AD to the Civil Aviation Safety Regulations 1998 scheme.

Reference to CASR authority

• The opening paragraph of the AD states that it is issued under subregulation 39.1(1) of CASR 1998 and that the delegate requires action necessary to correct the unsafe condition to be taken in relation to the aircraft. That placement ties the AD’s requirements to the overarching airworthiness regulatory regime under CASR. The AD itself does not reproduce the text of subregulation 39.1(1) but invokes it as the basis for the delegate’s power to require corrective actions.

Manufacturer service documents as compliance instruments

• The AD requires compliance “in accordance with the Accomplishment Instructions” of Boeing SBs and ASBs (specific numbers, revisions and dates are cited). Those manufacturer documents are therefore incorporated by reference into the regulatory obligation. This practice aligns with standard airworthiness regulation where manufacturers’ service bulletins provide the technical method to achieve the directive’s intent. Operators must therefore coordinate compliance in ways that respect both CASA’s AD and the content of the Boeing documents.

Cross-reference to FAA AD

• The AD notes FAA AD 2004-11-03 Amdt 39-13648 (Note 2). That cross-reference indicates that a corresponding FAA directive exists for the unsafe condition. For operators subject to both CASA and FAA oversight, the existence of a counterpart FAA AD can affect maintenance planning, particularly for operators that must demonstrate compliance to multiple authorities.

Interaction with operator manuals and maintenance programs

• The AD’s inspection and “before further flight” repair requirements interact with an operator’s approved maintenance program, minimum equipment list (if relevant), and flight operations procedures. The AD does not stipulate amendments to an operator’s manuals; operators will be required to update maintenance planning documents to accommodate AD inspection intervals, repair processes and terminating modification scheduling, consistent with their obligations under CASR.

Parts and airworthiness approval processes

• The AD mandates replacement parts and installations per Boeing SBs/ASBs. Installation of replaced components and structural changes may require record-keeping and potentially a maintenance release or certificate of release to service under CASR. The AD itself does not spell out certifying processes, but compliance will necessarily interact with the statutory record-keeping and certification requirements in CASR and the operator's continuing airworthiness obligations.

International operations and airworthiness directives

• The AD’s explicit reference to the FAA AD indicates harmony between the Australian and US regulatory assessments of the underlying unsafe condition. Where aircraft operate internationally, compliance may also need to reflect directives issued by other competent authorities; the AD does not expand on international coordination but signals alignment with the FAA.

No explicit interaction with criminal or civil law in the AD text

• The AD does not refer to criminal sanctions, civil liability rules, contract law, or insurance clauses. However, non-compliance with an airworthiness directive can have downstream effects in those domains (for example, affecting insurability or liability in the event of an incident). Those interactions are not described in the AD and would be governed by separate legal regimes and contractual terms.

The AD includes internal references to the revision history and dates of the Boeing service documents that it mandates, and it contains issuance and notification dates for the AD itself. The AD text is the sole source of documented amendment history supplied here.

Service document revisions cited in the AD

• Boeing Service Bulletin (SB) 747-24A2240: the AD requires work “per the Accomplishment Instructions of Boeing Service Bulletin (SB) 747-24A2240, Revision 1, dated 20 February 2003” for Requirement 1 and Requirement 2. The AD therefore incorporates Revision 1 of SB 747-24A2240, dated 20 February 2003.
• Boeing Alert Service Bulletin (ASB) 747-24A2247: Requirement 3 and Requirement 4 refer to the Accomplishment Instructions of Boeing Alert Service Bulletin 747-24A2247, dated 10 July 2003. The AD cites the ASB by date but does not list a revision number for that ASB.
• Boeing SB 747-24A2242 Revision 1 dated 14 August 2003: Requirements 5 and 6 require accomplishment in accordance with SB 747-24A2242 Revision 1, dated 14 August 2003. The AD explicitly identifies Revision 1 and date for this SB.
• Boeing ASB 747-24A2243 dated 31 October 2002: Requirement 7 refers to ASB 747-24A2243, dated 31 October 2002; again the AD cites the ASB by date.

AD issuance and notification dates

• The AD includes the signature of James Coyne, Delegate of the Civil Aviation Safety Authority, dated 23 June 2004.
• The AD states that it becomes effective on 5 August 2004 (final line of Compliance section).
• The AD was notified in the Commonwealth of Australia Gazette on 14 July 2004, as noted at the end of the AD.

Cross-reference to FAA AD

• Note 2 in the AD states: “FAA AD 2004-11-03 Amdt 39-13648 refers.” That is an external regulatory document with its own amendment history, included here as a cross-reference but not reproduced.

No subsequent amendments or revocations recorded in the AD

• The supplied AD text does not contain subsequent amendments to the AD itself (for example, changes to compliance times or to the referenced service documents after the issuance date). The AD text appears as a single directive with the dates and SB/ASB revisions identified above. Any later amendments, superseding ADs, or amendments to the cited Boeing documents are not contained within this AD text and are not part of this source.

Practical consequence

• Operators must ensure they use the exact service bulletin revisions and dates cited in the AD when performing the mandated actions, because the AD explicitly ties compliance to those numbered, dated documents (for example, SB 747-24A2240 Revision 1 dated 20 February 2003; SB 747-24A2242 Revision 1 dated 14 August 2003). Using later revisions or alternative methods might require approval from CASA if those later revisions are not automatically incorporated by the AD.

The AD text supplied contains no litigation history. There are no cases, appeals, or judicial reviews mentioned in the AD. The document records the administrative issuance process,signed by the CASA delegate on 23 June 2004 and notified in the Commonwealth Gazette on 14 July 2004,but includes no record of legal challenge, enforcement action, or court proceedings within the text provided.

What the AD does provide

• The AD cross-references FAA AD 2004-11-03 Amdt 39-13648 (Note 2). The AD does not report any litigation or dispute about that FAA AD; it merely notes the FAA reference.

Implication for research

• To obtain a litigation history (if any) arising from this AD, an independent search outside this AD text is required. The AD itself does not document appeals to CASA, requests for exemptions, variations, or any court proceedings. The absence of litigation references in this AD should not be taken as confirmation that no litigation has ever occurred; it only reflects that the supplied AD text contains no litigation history.

The AD contains several procedural and practical features that can create operational pitfalls if not managed exactly as written. These are practical “gotchas” drawn directly from the AD text and its interplay with operational practice.

Applicability narrowness and line-number risk

• The AD applies only to Model 747-400 and -400F series aeroplanes having line numbers 696 through 1310 inclusive and equipped with Rolls-Royce engines. Operators must verify the aircraft line number and engine manufacturer to determine applicability. Misidentifying applicability (for example, assuming all 747-400s are covered) can result in unnecessary work or, conversely, missed compliance.

Definition of “general visual inspection”

• Note 1 defines the inspection standard tightly: it is limited to detection of “obvious damage, failure or irregularity,” from touching distance, under normal lighting, and may require removal or opening of access panels and use of mirrors and platforms. This is not an intrusive structural inspection. Operators must ensure that maintenance personnel apply the correct inspection standard. Overlooking the need to remove panels or to use a mirror where necessary could result in missed damage findings that the AD intended to have detected.

“Before further flight” repairs are mandatory

• Requirements 2 and 4 require that any damage found be repaired “before further flight.” That language makes any damage finding immediately operationally material and may result in aircraft being grounded until repairs are completed per the cited Boeing documentation. Planning for parts availability, skilled labour and documentation is necessary to avoid extended downtime.

Terminating actions and timing trade-offs

• The AD allows operators to choose between continuing inspections every 10,000 hours TIS or completing terminating modifications within 48 months. Operators that delay terminating modifications retain the recurring inspection and potential grounding exposure on damage findings. Conversely, undertaking terminating modifications requires one-time expenditure and downtime. The AD does not mandate which path to take but sets the deadlines; operators must weigh the cost and scheduling trade-offs carefully.

Exact service documents and revisions

• The AD mandates compliance “in accordance with the Accomplishment Instructions” of specific Boeing SBs and ASBs with stated revision numbers and dates (e.g. SB 747-24A2240 Revision 1, dated 20 February 2003; SB 747-24A2242 Revision 1, dated 14 August 2003). Using a different revision or an alternative repair method without CASA approval could be non-compliant. Operators must verify they have and follow the correct revision.

Pressurisation and leak-check requirement

• Requirement 6 requires pressurising the hydraulic system and examining new hydraulic lines and connectors for leaks after hydraulic-line replacement per Requirement 5, and repairing any leaks. This step must be completed before further flight and requires access to hydraulic system test capabilities. Failing to perform the leak check correctly could leave the aircraft non-compliant with the AD and potentially unsafe.

Interdependence of Requirements

• Accomplishment of Requirements 5 and 6 terminates the Requirement 1 repetitive inspections; accomplishment of Requirement 7 terminates the Requirement 3 repetitive inspections. Operators must track which terminating action corresponds to which inspection stream; completing one terminating action does not terminate both inspection streams unless both are completed as specified.

Cross-jurisdictional expectations

• The AD notes FAA AD 2004-11-03 Amdt 39-13648 in Note 2. Operators subject to both CASA and FAA oversight should ensure they satisfy both regulators’ expectations; assuming that compliance with one regulator equals compliance with the other without verification of any textual differences can be risky.

Record retention and certification

• The AD does not set out explicit record submission or amendment procedures, but maintenance performed in accordance with the AD will need to be recorded and the aircraft released to service under applicable CASR requirements. Operators should ensure that their records document the specific SB/ASB references and the nature of any repairs and modifications in case of later audit or inspection.

Time-window sequencing

• Initial inspections must be done within 90 days after the effective date of the AD, which became effective on 5 August 2004. The AD’s timeline obligations are absolute from the effective date; failing to plan for inspection slots may lead to non-compliance. Also, inspections repeat every 10,000 hours TIS until termination by the specified modifications,operators must track TIS carefully.

No explicit alternative compliance path in the AD

• The AD prescribes the Boeing accomplishment instructions as the compliance path; it does not articulate an alternative method of compliance (AMOC) procedure within the text. If an operator seeks to use a different repair method or a different parts source, they will need to obtain whatever regulatory approvals CASA requires under the CASR framework; the AD itself does not provide the AMOC mechanism.

Compliance with the AD requires following the timing and method prescriptions in the Requirement and Compliance sections and performing the necessary documentation and certification steps under CASR-adopted practice. The AD explicitly ties compliance work to specific Boeing service documents and sets inspection intervals, repair timing and terminating action deadlines.

Step-by-step compliance checklist (operator perspective)

1. Applicability check

   • Confirm whether each 747-400 or 747-400F in the fleet has a line number between 696 and 1310 inclusive and is equipped with Rolls-Royce engines. Only aircraft meeting both criteria are subject to the AD.

2. Obtain the required Boeing publications

   • Acquire the exact Boeing documents cited: SB 747-24A2240 Revision 1 dated 20 February 2003; ASB 747-24A2247 dated 10 July 2003; SB 747-24A2242 Revision 1 dated 14 August 2003; ASB 747-24A2243 dated 31 October 2002. Use those documents’ Accomplishment Instructions as the technical methods to carry out inspections, repairs and replacements.

3. Schedule initial inspections within 90 days

   • For each affected aircraft, schedule and perform: a) Requirement 1 inspection: general visual inspection for damage or arcing of the IDG power feeder cables and cable conduit in the forward section of all four engine struts, in accordance with SB 747-24A2240 Rev 1, within 90 days of the AD effective date (Compliance for Requirement 1). b) Requirement 3 inspection: general visual inspection for chafing and arcing damage of the power feeder cables and hydraulic lines on each outboard strut aft of the block clamp, in accordance with ASB 747-24A2247, within 90 days of the AD effective date (Compliance for Requirement 3).

4. Apply the “general visual inspection” standard correctly

   • Follow Note 1’s definition: inspect from touching distance under normally available lighting, use mirrors where needed, and remove panels or use stands/ladders as necessary to gain proximity. Document the inspection findings with photos and maintenance entries to demonstrate adherence to the AD’s inspection standard.

5. Repair any damage found before further flight

   • If Requirement 1 inspections reveal damage or arcing, perform repairs in accordance with the Accomplishment Instructions of SB 747-24A2240 Revision 1 and ensure repairs are completed before further flight (Requirement 2).
   • If Requirement 3 inspections reveal chafing or arcing damage, perform repairs in accordance with ASB 747-24A2247 and ensure repairs are completed before further flight (Requirement 4).
   • Ensure parts and approved repair materials from the Boeing SB/ASB are used and that the repair is signed off by authorised maintenance personnel in line with CASR maintenance release requirements.

6. Decide whether to accomplish terminating modifications

   • Evaluate costs, downtime, and operational impact of: a) Requirement 5/6 package: remove conduit, install new shield/bracket assembly and replace two hydraulic lines in each engine strut (SB 747-24A2242 Rev 1), then pressurise hydraulic system and check for leaks, repairing as necessary. Compliance window: within 48 months; completion terminates Requirement 1 repetitive inspections. b) Requirement 7: replace the wiring and hydraulic tubing support bracket (ASB 747-24A2243). Compliance window: within 48 months; completion terminates Requirement 3 repetitive inspections.
   • If electing terminating modifications, schedule parts procurement and MRO time within the 48-month window. If electing to defer modifications, plan for ongoing 10,000-hour TIS inspections.

7. If performing terminating modifications, follow post-installation checks

   • After hydraulic-line replacement (Requirement 5), pressurise the hydraulic system and inspect for leaks and repair any leaks before further flight (Requirement 6). Document the pressurisation test and any corrective action taken.

8. Maintain inspection interval discipline

   • If terminating modifications are not yet accomplished, repeat Requirement 1 and Requirement 3 inspections at intervals not exceeding 10,000 hours TIS as specified. Keep accurate TIS logs to ensure inspections are scheduled and completed on time.

9. Record-keeping and certification

   • Record each inspection, repair, modification and pressurisation test in the aircraft’s maintenance records. Reference the specific Boeing SB/ASB (by number, revision and date) and the AD reference (AD/B747/307). Ensure maintenance releases or certificates of release to service are executed according to CASR requirements upon completion.

10. Coordinate with other regulatory obligations

• Note the cross-reference to FAA AD 2004-11-03 Amdt 39-13648 and confirm whether parallel FAA compliance is required for your operations. If operating in multiple jurisdictions, ensure any differences in requirements are addressed.

11. If alternative methods are proposed

• The AD does not describe an AMOC process in its text. If you intend to use an alternative repair method, different parts, or a different service bulletin revision, obtain the necessary CASA approvals as required under CASR processes before proceeding.

12. Risk management and logistics

• Anticipate the operational impact of “before further flight” grounding for aircraft with detected damage. Plan spare aircraft, adjust schedules, and ensure parts and qualified technicians are available to minimise downtime.

13. Audit readiness

• Be prepared to show CASA inspectors or auditors that inspections and repairs were performed in accordance with the specified Boeing documents and the AD timelines. Maintain photographic evidence, SB/ASB references, and maintenance release entries.

14. Monitor for later amendments

• The AD cites particular SB/ASB revisions and dates. Monitor CASA communications for any superseding ADs or amendments that modify compliance timelines, incorporate later SB revisions, or alter methods of compliance.

By following these steps, operators and maintenance organisations will meet the AD’s prescriptive inspection, repair, modification and documentation obligations as stated in the Requirement and Compliance sections. The AD ties legal compliance to both the timelines (90 days initial, 10,000 hours TIS repeat, 48 months for terminating actions) and the manufacturer’s accomplishment instructions cited explicitly in the AD.