AD/B747/369 - Passenger Oxygen Masks

The Directive rests on a few concise technical and regulatory concepts that determine both practical compliance and the distribution of responsibilities.

Applicability and scope. The Directive applies only to Boeing 747-200B, 747-300 and 747-400 series aeroplanes “as identified in Boeing Service Bulletin (SB) 747-35-2119, dated 30 November 2006.” That phrase places primary reliance on the SB to identify the exact fleet subsets and installations covered. The Directive lists precise locations where oxygen masks and their oxygen boxes are to be inspected: passenger service units (outboard and centre main deck), flight attendant service units, flightcrew rest compartments, both upper and lower modules of the door 5 overhead crew rest, lavatory modules, and “miscellaneous ceiling panels, as applicable.” The inclusion of “as identified” and “as applicable” means the SB’s aircraft-specific applicability matrix will control which individual aeroplanes and which specific mask locations are in scope.

Inspection as determinative step. Requirement 1 is a general visual inspection to determine two discrete data points for each oxygen mask in the listed locations: the manufacturer and the manufacture date. The Directive does not require immediate replacement of all masks; it uses the inspection to identify which masks are from manufacturers or manufacture dates that require further investigation or corrective action under the SB’s Accomplishment Instructions.

Corrective action standard. Requirement 2 instructs operators to perform “all the applicable related investigative and corrective actions by accomplishing all of the applicable actions specified in the Accomplishment Instructions of SB 747-35-2119,” except it clarifies replacement expectations: where the SB specifies replacing the oxygen mask assembly with a new assembly, the Directive requires replacement with “a new or modified oxygen mask assembly having an improved flow indicator.” This makes the “improved flow indicator” the performance characteristic that the Directive requires in substituted parts.

Dependence on manufacturer service information. The Directive explicitly references Boeing SB 747-35-2119 (30 November 2006) as the procedural source for inspection and corrective steps. It also records that SB 747-35-2119 refers to B/E Aerospace SB 174080-35-01 (6 February 2006) and Revision 1 (1 May 2006) as sources for modifying the oxygen mask assembly to replace the flow indicator. Therefore operators must consult and follow the Accomplishment Instructions contained in the stated SBs to comply.

Interaction with FAA processes. The Directive accepts later revisions of the Boeing SB where those revisions have been approved by the FAA as an AMOC to FAA AD 2007-26-06; such revisions are “considered acceptable for compliance with the equivalent Requirements of this Directive.” The Directive therefore sets up a delegated interoperability in which FAA approvals of SB revisions function as acceptable alternate methods for compliance with CASA’s Directive.

Safety rationale. The background records two FAA-source claims: (1) the FAA received a report that several passenger masks with broken in-line flow indicators were found following a mask deployment; and (2) the safety consequence if flow indicators fracture and separate is “which could inhibit oxygen flow to the masks and consequently result in exposure of the passengers and cabin attendants to hypoxia following a depressurisation event.” The Directive therefore links a field finding to a potential catastrophic safety outcome and prescribes inspection and correction targeted at the flow indicator component.

Temporal effect and operational constraint. The compliance timing splits out a long window for the initial inspection (60 months from effective date), but imposes an immediate operational constraint: any corrective action identified after the inspection must be completed “before further flight.” That phrase establishes a stop-fly condition on any aircraft that, after inspection, is found to require corrective measures under the SB.

Authority and signature. The document is signed by a CASA delegate, Charles Lenarcic, and dated 20 December 2007, with the AD becoming effective 14 February 2008. The instrument is therefore presented as a directive issued under the authority of CASA, using the FAA materials as comparative technical sources.

The primary, direct addressees of the Directive are operators, owners, and maintenance organisations responsible for Boeing 747-200B, 747-300 and 747-400 series aeroplanes that are identified within Boeing SB 747-35-2119 dated 30 November 2006. The Directive’s Applicability clause ties coverage to the SB’s identification of aircraft, so anyone operating or maintaining aircraft listed in that SB is within scope. Specifically, the following actor groups are affected:

• Airline operators and aircraft owners: They are responsible for scheduling and accomplishing the Requirement 1 general visual inspection within the 60-month window, and for ensuring corrective actions from Requirement 2 are accomplished before further flight when triggered by the inspection. The compliance timing and “before further flight” condition create direct operational obligations for operators who must manage maintenance, parts procurement and flight scheduling to meet the AD.

• Maintenance, repair and overhaul organisations (MROs) and certificated maintenance personnel: The Directive requires inspections and potentially corrective modifications or replacements “in accordance with SB 747-35-2119.” MROs performing these tasks must have access to, and follow, the Accomplishment Instructions in the specified Boeing and B/E Aerospace service bulletins and must ensure replacements meet the Directive’s specification of “new or modified oxygen mask assembly having an improved flow indicator” where replacement is specified.

• Parts manufacturers and suppliers (B/E Aerospace and others): The Directive references B/E Aerospace SB 174080-35-01 and its Revision 1 as sources for modifying the oxygen mask assembly to replace the flow indicator. Where replacements or modifications are required, demand will fall on suppliers able to provide compatible assemblies with the improved flow indicator. The SB cross-references indicate that the manufacturers named in the SBs are directly relevant to the technical specification of the corrective parts.

• Regulatory and compliance personnel within operators: Responsible for determining which aircraft are identified in the governing SB (as the AD’s applicability depends on that identification), recording compliance, and ensuring that any later SB revisions approved by the FAA as AMOC are reviewed for acceptance under this AD.

• Flight crew and cabin crew indirectly: The safety outcome targeted by the Directive,reducing the risk that an in-line flow indicator fractures and inhibits oxygen flow,relates directly to passenger and cabin crew safety in the event of a depressurisation. While the Directive does not impose actions on crew members themselves, crew operating affected aircraft rely on operators and maintenance providers to accomplish the required inspections and corrective actions to maintain compliance and safety.

• Lessors and financiers with 747 assets: Lessors of affected aircraft will need to ensure lessees comply, particularly since the AD imposes an inspection that identifies manufacturer and manufacture date and may necessitate replacement of equipment before further flight. The Directive’s reliance on the SB to identify applicability may require coordination between lessors and lessees to determine which aircraft are in scope.

• CASA and FAA interface staff: The Directive explicitly accepts later revisions of Boeing SB 747-35-2119 approved by the FAA as AMOCs to FAA AD 2007-26-06, thus creating a required interplay between CASA’s acceptance and FAA approvals. Regulatory staff must therefore track FAA AMOCs and SB revisions to determine whether they can lawfully be relied upon for compliance under this AD.

In sum, the immediate financial and operational burden falls on commercial operators and their MRO vendors who must perform the inspections, document manufacture/manufacturer dates, and, where required, modify or replace oxygen mask assemblies with versions that incorporate the improved flow indicator. The Directive does not itself allocate costs or provide exemptions; it prescribes technical steps linked to service-bulletin instructions and sets a timeframe and a “before further flight” requirement for remediation.

Duties imposed by the Directive are specific and procedural. The Directive lays out the following concrete duties for operators and maintenance organisations:

• Conduct the prescribed inspection. Under Requirement 1, operators must “carry out a general visual inspection in accordance with SB 747-35-2119 to determine the manufacturer and manufacture date of the oxygen masks” in the enumerated locations (passenger service units, flight attendant service units, flightcrew rest, door 5 overhead crew rest modules, lavatory modules, and miscellaneous ceiling panels). The duty specifies the method source , the Boeing SB , and the data to be recorded (manufacturer and manufacture date).

• Perform all applicable related investigative and corrective actions. Under Requirement 2, following the Requirement 1 inspection, operators must “carry out all the applicable related investigative and corrective actions by accomplishing all of the applicable actions specified in the Accomplishment Instructions of SB 747-35-2119.” This means the SB’s Accomplishment Instructions determine the applicable follow-up tasks and must be followed in full for those tasks deemed applicable.

• Ensure replaced assemblies have improved flow indicators. The Directive adds a specific hardware requirement for any replacement scenario: “except where the service bulletin specifies replacing the oxygen mask assembly with a new oxygen mask assembly, replace it with a new or modified oxygen mask assembly having an improved flow indicator.” Therefore, where replacement is specified, the replacement assembly must embody the improved flow indicator design.

• Meet required timing. Operators must complete Requirement 1 within 60 months after the Directive’s effective date. Requirement 2, if applicable, must be completed before further flight after the Requirement 1 inspection. The “before further flight” requirement imposes an immediate ground constraint on any aeroplane that, following inspection, requires corrective action under the SB.

Rights and permissible alternatives recognised by the Directive:

• Use of later FAA-approved SB revisions as AMOC. The Directive explicitly allows “later revisions of the above Boeing SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-26-06,” to be considered acceptable for compliance with the equivalent requirements of this Directive. That operates as a right to rely on FAA AMOC approvals of Boeing SB revisions to satisfy CASA’s requirements in respect of the equivalent actions. The practical effect is that operators who choose to use a later Boeing SB revision may do so,if it has FAA AMOC status,without seeking a separate CASA-approved alternative, provided CASA accepts the FAA approval as the Directive states.

• Use of B/E Aerospace SB as additional service information. Note 1 in the Directive records that SB 747-35-2119 references B/E Aerospace SB 174080-35-01 and Revision 1 as “additional sources of service information for modifying the oxygen mask assembly by replacing the flow indicator with an improved flow indicator.” The Directive therefore recognises these B/E Aerospace SBs as sources to be consulted when performing the modification required to achieve the improved flow indicator.

• No express waiver or exemption mechanism within the AD text. The Directive does not include an express CASA-granted mechanism for obtaining exemptions, alternative compliance methods (other than the acceptance of FAA-approved SB revisions as AMOC), or staged compliance beyond the stated 60-month window. The only explicit alternate-route recognition is the FAA-approved AMOC route stated.

Operational duties implied by the Directive:

• Record-keeping and traceability. The inspection to determine manufacturer and manufacture date creates an implicit duty to record and retain those inspection findings in a traceable manner sufficient to demonstrate compliance, especially because corrective actions are conditional on the inspection outcomes specified in the SB.

• Parts procurement and installation. Where the SB prescribes replacement or modification to introduce an improved flow indicator, operators and MROs must source and install assemblies that conform to the SB instructions and the Directive’s requirement that replacements have the improved flow indicator.

• Scheduling to avoid or manage “before further flight” constraints. Because Requirement 2 must be satisfied before further flight where corrective work is needed, operators must be able to ground affected aeroplanes until remedial work is completed, or otherwise manage scheduling and fleet deployment to maintain operations while completing the mandated works.

The Directive therefore frames a set of specific duties tied to a technical service bulletin, a hardware performance characteristic (improved flow indicator), and clear timing constraints, while providing a limited recognition of FAA AMOC approvals as an acceptable alternate route for compliance.

The text of the Directive itself, as provided, does not include any express penalty provisions, administrative sanction schedules, or enforcement procedures. The Directive states what actions must be accomplished, the applicable service bulletins to be followed, the compliance timeframes, and the effective date; it does not in the body of the reproduced text set out penalties for non-compliance nor detail enforcement mechanisms or administrative processes that CASA will use to verify compliance.

Despite the absence of expressed penalty clauses in the Directive text, the document is presented as an Airworthiness Directive issued by CASA and made “effective” on a specified date. The AD’s labeling and framing indicate it is a mandatory safety directive; however, the AD text does not itself define the regulatory enforcement tools or sanctions that CASA may apply for non-compliance. No infringement fines, certificate actions, or prosecution details are included in the reproduced wording.

Practical enforcement implications that can be read from the Directive text itself are limited to the compliance demands: the inspection must be completed within 60 months, and applicable corrective actions must be completed before further flight after inspection when required. The operational effect of “before further flight” is that an aeroplane that, after inspection, requires remedial work cannot be flown until that work is finished. The AD therefore imposes a de facto operational enforcement effect by conditioning further flight on the completion of corrective actions identified by the inspection, but it does not describe the administrative steps CASA will take to monitor or enforce that condition in the text supplied.

The Directive records its issuance and the signature of a CASA delegate, Charles Lenarcic, dated 20 December 2007, and the stated effective date is 14 February 2008. No litigation, sanction, or compliance-audit language is present in the document as provided.

Readers should note that while this Directive does not itself list penalties, CASA and national aviation regulatory frameworks commonly implement ADs as mandatory requirements enforceable under broader statutory or regulatory regimes; however, any statement about specific fines, demerit systems, or enforcement processes would rely on materials outside the AD text provided and is not contained in the source material reproduced here.

Within the text of the Directive, the primary cross-references are to the FAA’s regulatory actions and to manufacturer service bulletins, rather than to statutory Acts or other domestic regulations. The Directive explicitly references FAA AD 2007-26-06 (Amdt 39-15308) in Note 2 and accepts later revisions of Boeing SB 747-35-2119 that are approved by the FAA as an Alternate Method of Compliance to FAA AD 2007-26-06 as acceptable to comply with the equivalent requirements of the CASA Directive. The Directive therefore sets a formal pathway for FAA approvals of Boeing SB revisions to serve as acceptable alternate methods for CASA compliance, aligning CASA’s technical compliance acceptance with FAA-approved AMOCs in respect of that specific Boeing SB.

The Directive also references Boeing SB 747-35-2119 (30 November 2006) as the primary service-information instrument for performing the inspections and corrective actions, and it notes that SB 747-35-2119 itself refers to B/E Aerospace SB 174080-35-01 (6 February 2006) and Revision 1 (1 May 2006). The inclusion of those service bulletins creates a chain of technical documents that instruct maintenance and modification actions required to comply with the AD. In practice, service bulletins are manufacturer-issued instructions that, when incorporated by an AD, become mandatory actions to satisfy the AD’s requirements.

The Directive does not reference any particular Australian Acts, civil aviation regulations, or penalty regimes in its text. It also does not recite any domestic legislative provision authorising CASA to issue Airworthiness Directives; the AD is presented as an issued instrument with an effective date and a CASA delegate signature, but the statutory source of CASA’s general powers is not reproduced in the text supplied.

The bilateral regulatory interaction represented here is therefore limited to the AD’s acceptance of FAA AMOCs and the AD’s cross-reference to manufacturer service bulletins that themselves reference other service information. The Directive thereby creates a practical dependency whereby operators may rely on FAA-approved AMOCs to later Boeing SB revisions for compliance, and must follow the Accomplishment Instructions in the specified SBs (and referenced B/E Aerospace SB) to perform the inspection and any required corrective actions.

No other domestic or international law interactions, treaty references, or regulatory harmonisation statements are present in the reproduced Directive text. Specifically, the Directive does not explicitly state how CASA will treat FAA ADs in general, nor does it describe a general equivalency framework beyond the single sentence accepting later Boeing SB revisions approved by the FAA as AMOCs for FAA AD 2007-26-06. Any further interaction with Australian aviation law, operator certificates, or enforcement regimes is not contained within this Directive’s text as provided.

The reproduced Directive does not contain a sequence of amendments to AD/B747/369 beyond its initial issuance. What the text does contain relevant to amendment is the following items:

• The Directive recognises that “Later revisions of the above Boeing SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-26-06, are considered acceptable for compliance with the equivalent Requirements of this Directive.” That language permits future technical revisions to the referenced Boeing service bulletin, once those revisions have FAA AMOC approval with respect to FAA AD 2007-26-06, to be used to demonstrate compliance with this CASA AD. In practice, that is not an amendment to the Directive itself, but it is an allowance that links Boeing SB revision history and FAA AMOC decisions into the set of acceptable compliance materials.

• The Directive includes Note 1, which records that Boeing SB 747-35-2119 refers to B/E Aerospace SB 174080-35-01 dated 6 February 2006 and Revision 1 dated 1 May 2006, as additional sources. Note 1 is not an amendment but records the service-bulletin landscape referenced by the AD at time of issue.

• The AD provides two dates relevant to its history: signed on 20 December 2007 and “effective on 14 February 2008.” No subsequent amendment dates, superseding AD numbers, cancellations, or revision notices to AD/B747/369 are included in the text provided.

• The background references FAA AD 2007-26-06 Amdt 39-15308; however the Directive does not itself record any update history in relation to that FAA AD other than accepting FAA-approved Boeing SB revisions as acceptable AMOCs for compliance with equivalent CASA requirements.

Therefore, according to the text supplied, AD/B747/369 stands as issued on 20 December 2007, effective 14 February 2008, with the AD’s ongoing acceptability of later FAA-approved Boeing SB revisions to serve as AMOCs. The Directive text does not record any subsequent amendments to the AD itself, nor does it include version control or an amendment log. If an operator requires a formal amendment history of the AD (for example, to confirm whether CASA has since varied, superseded, or cancelled the AD), those records will need to be obtained from the CASA AD registry or other official CASA publications, because such subsequent amendment information is not present in the text provided.

The Directive text provided contains no record of litigation, legal challenges, judicial review, administrative appeals, or enforcement proceedings arising out of AD/B747/369. There is no mention in the document of any disputes, appeals, or legal proceedings either pending or concluded relating to the content, issuance, or implementation of this AD.

The AD does reference FAA AD 2007-26-06 and notes FAA-sourced field reports that informed the safety rationale, but it does not record any legal actions connected to FAA AD 2007-26-06 within this text. No case names, tribunal decisions, or judicial findings are included or cited in the Directive.

Therefore, based solely on the text provided, there is no litigation history available or recorded. Practitioners seeking to know whether this Directive has been challenged or whether compliance obligations under it have been the subject of judicial review will need to consult external legal databases, CASA enforcement records, tribunal or court archives, or contemporaneous regulatory filings. Those sources, however, fall outside the content of the Directive itself as reproduced here.

The Directive contains several points that commonly generate operational, compliance, or interpretation risks; these items are explicit or implicit in the requirements and notes, and they can produce implementation surprises if not addressed deliberately.

Applicability depends on the service bulletin’s identification. The AD’s applicability clause limits coverage to “Model 747-200B, 747-300 and 747-400 series aeroplanes, as identified in Boeing Service Bulletin (SB) 747-35-2119, dated 30 November 2006.” That means an operator cannot simply rely on model type alone; they must consult Boeing SB 747-35-2119 to determine whether a particular airframe serial or configuration is included. Failure to consult the SB’s applicability matrix may lead to under- or over-inclusion of aircraft and consequent compliance errors.

Inspection scope is detailed but includes “as applicable” language. Requirement 1 lists multiple modules and locations, and adds “together with miscellaneous ceiling panels, as applicable.” Ambiguity can arise on what exactly is “miscellaneous ceiling panels” for a particular installation. Operators should ensure that they translate the SB’s inspection drawings and parts lists into concrete lists of locations for each airframe; otherwise maintenance may miss required inspection sites or perform unnecessary work on unaffected locations.

The inspection determines manufacturer and manufacture date, not immediate replacement. The first required action is a general visual inspection to determine manufacturer and manufacture date. That could be misread as an immediate replacement mandate. The actual replacement or modification duty is conditional on the SB’s Accomplishment Instructions; operators must therefore follow the SB’s logic that links specific manufacturers/manufacture dates to required corrective actions. Misreading the initial inspection as a blanket call to replace will raise unnecessary costs.

“Before further flight” creates an immediate operational constraint. Requirement 2 conditions corrective actions to be performed “before further flight after the Requirement 1 inspection.” If an inspection reveals a mask that requires corrective action, that aeroplane cannot be flown until corrected. This can create immediate AOG (aircraft on ground) situations if not planned for, with consequential schedule and revenue impact. Operators should ensure that planned inspections are scheduled to avoid vulnerable operational windows and that parts and labour for likely corrective actions are available.

Requirement 2’s replacement specification is precise about the improved flow indicator. Where the Boeing SB calls for replacement, the AD requires that such replacement be “with a new or modified oxygen mask assembly having an improved flow indicator.” If a parts supplier provides a nominally “new” assembly that nevertheless does not have the “improved flow indicator” design, the operator will not be in compliance. Procurement checks must therefore verify that the specific flow-indicator design is present.

Dependency on multiple service bulletins and on FAA AMOCs. The AD instructs compliance “in accordance with SB 747-35-2119” and records that that SB refers to B/E Aerospace SB 174080-35-01 and Revision 1 as additional information for the modification. Operators must therefore assemble and follow multiple service-bulletin documents. The AD also permits the use of later revisions of the Boeing SB if approved by the FAA as an AMOC to FAA AD 2007-26-06. Operationally, that reliance on FAA-approved AMOCs means an operator using a later Boeing SB revision must ensure it carries FAA AMOC approval , otherwise CASA will not necessarily treat it as an acceptable compliance method under this AD.

Long inspection window may encourage delay. Requirement 1 must be done “within 60 months after the effective date” of the AD. A 60-month window may encourage operators to defer inspections to the outer limit, which increases the period during which an undetected hazardous condition might persist. The safety background indicates that flow-indicator fractures were observed in field-deployed masks; deferral choices thus trade short-term scheduling convenience against prolonged exposure to the identified risk.

Record-keeping implicit but not spelled out. The AD requires determination of manufacturer and manufacture date via a general visual inspection but does not prescribe record-keeping standards in the text supplied. Operators must nonetheless maintain auditable records to demonstrate compliance, particularly when an inspection triggers corrective actions that must be performed before further flight. Lack of explicit record-keeping rules can cause later disputes as to whether the inspection was completed in accordance with the SB.

Parts supply and modification availability. The AD’s call for replacement or modification to a “new or modified oxygen mask assembly having an improved flow indicator” presumes that such modified or new assemblies are available. If a given operator discovers an unexpected number of masks requiring replacement, limited supplier stock or lead times could lengthen grounding times or require sourcing from alternate suppliers. The AD text does not provide transitional relief in such supply-constrained scenarios.

No penalties or enforcement process set out in the AD text. The absence of explicit penalties in the Directive text might mislead some readers into thinking that only voluntary compliance is expected; the AD is presented as an issuing CASA instrument and carries mandatory wording, but the enforcement mechanisms are not described in the AD itself. Operators should not infer leniency from the absence of penalty language contained in the AD document.

Cross-referencing FAA AD without defining CASA acceptance mechanics. The AD accepts FAA-approved Boeing SB revisions as AMOCs, but the exact CASA process by which an operator can rely on such FAA approvals for CASA compliance is not described. This could cause uncertainty, particularly where operators seek to rely on AMOCs before any formal CASA confirmation.

In short, the main “gotchas” are: reliance on other documents for final applicability; the conditional but binding nature of “before further flight” corrective actions; the need to verify that replacement assemblies actually contain the improved flow indicator; scheduling and supply risks around the 60-month inspection window; and record-keeping and proof-of-compliance gaps that are not detailed in the AD text.

Compliance with AD/B747/369 requires a combination of document review, physical inspection, parts procurement, and record-keeping. The Directive ties required actions to Boeing SB 747-35-2119 (dated 30 November 2006) and references B/E Aerospace SB 174080-35-01 (6 February 2006) and Revision 1 (1 May 2006) as additional modification guidance. Operators should adopt the following practical step-by-step compliance process based on the Directive’s own wording.

1. Confirm applicability by consulting Boeing SB 747-35-2119 (30 November 2006). The AD’s applicability clause is explicit: the AD applies to “Model 747-200B, 747-300 and 747-400 series aeroplanes, as identified in Boeing Service Bulletin (SB) 747-35-2119, dated 30 November 2006.” Obtain the SB and verify whether each airframe in your fleet is listed. The SB will identify specific airframe serials, configurations, and affected installations.

2. Schedule Requirement 1 inspection within the 60-month window. The AD requires the general visual inspection of oxygen masks to be completed “within 60 months after the effective date of this Directive.” The AD’s effective date is 14 February 2008; accordingly, operators should schedule and complete the inspections no later than the end of that 60-month period. Given the “before further flight” consequence for corrective actions discovered during the inspection, scheduling inspections during planned maintenance or when spare aircraft capacity exists will mitigate operational disruption.

3. Perform the general visual inspection in accordance with SB 747-35-2119. Requirement 1 instructs: “Carry out a general visual inspection in accordance with SB 747-35-2119 to determine the manufacturer and manufacture date of the oxygen masks” in the enumerated locations (passenger service units , outboard and centre main deck; flight attendant service units; flightcrew rest; upper and lower module of door 5 overhead crew rest; lavatory modules; miscellaneous ceiling panels, as applicable). Ensure maintenance personnel consult the SB’s Accomplishment Instructions, inspection drawings, and parts lists so that the inspection scope for each airframe is clear and complete.

4. Record inspection findings and determine applicability of further actions. The inspection must determine manufacturer and manufacture date for each mask. Record these data points in an auditable manner (logbook entries, maintenance records, electronic records) against the specific aircraft and serial numbers. Cross-check the inspection results with the SB’s Accomplishment Instructions to determine which masks, if any, trigger related investigative or corrective tasks.

5. If the SB’s Accomplishment Instructions call for further investigation or corrective action, perform those actions before further flight. Requirement 2 mandates: “Following the Requirement 1 inspection carry out all the applicable related investigative and corrective actions by accomplishing all of the applicable actions specified in the Accomplishment Instructions of SB 747-35-2119 ... replace it with a new or modified oxygen mask assembly having an improved flow indicator.” Therefore, if the inspection identifies any masks that the SB’s instructions mark for corrective work, perform that work and ensure it is completed before the aircraft is next flown.

6. Ensure replacement assemblies meet the “improved flow indicator” requirement. Where the SB specifies replacement, the AD requires replacement with “a new or modified oxygen mask assembly having an improved flow indicator.” Procurement processes must therefore verify that parts ordered and delivered include the improved flow indicator design; parts documentation and supplier declarations should be retained as proof. If the SB prescribes a specific B/E Aerospace modification route, consult B/E Aerospace SB 174080-35-01 and Revision 1 as referenced in Note 1 for the particular modification instructions.

7. Consider using later Boeing SB revisions if FAA AMOC-approved. The AD allows “later revisions of the above Boeing SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-26-06” to be considered acceptable for compliance. If a later Boeing SB revision is available and carries FAA AMOC approval for the FAA AD, operators may elect to use that revision for compliance. Before doing so, confirm the FAA AMOC approval status and retain documentation of the FAA approval showing that the revision is an AMOC to FAA AD 2007-26-06.

8. Plan logistics to mitigate grounding risk. Because any corrective action discovered in Requirement 1 must be completed before further flight, schedule inspections and parts acquisition in a way that avoids long aircraft groundings. This may include staggering inspections across a fleet, pre-ordering parts expected to be required, or scheduling inspections to coincide with planned maintenance checks.

9. Maintain auditable records. Although the AD does not specify a record-keeping format, the conditional nature of the Requirement 2 “before further flight” duty effectively requires operators to retain inspection records, corrective-action records, parts identification and installation records, and any FAA AMOC documentation relied upon. These records should be organised by airframe, with serial numbers and dates of inspection and remedial action, and retained according to standard airworthiness and maintenance-record retention practices.

10. Coordinate with lessors, insurers and regulatory contacts. Where aircraft are leased, confirm with lessors whether they require notification or consent for inspection, modification, or replacement works. Similarly, coordinate with insurance underwriters if there is any exposure to increased premiums or material change in equipment specifications. Operators should also keep CASA informed of any compliance questions of interpretation that concern the AD’s applicability or execution, and should consult CASA guidance or formal AMOC processes if necessary.

11. Verify parts and MRO capability. Confirm that your maintenance provider or MRO has access to the necessary tools, technical data, and replacement or modification parts to implement the Accomplishment Instructions in the Boeing and B/E Aerospace SBs. If specialised parts or modifications are required (for example, to install the improved flow indicator), ensure the MRO has the necessary capability and certification to perform the work.

12. Document reliance on FAA-approved AMOC where used. If an operator relies on a later Boeing SB revision because it has FAA AMOC approval to FAA AD 2007-26-06, document that FAA AMOC approval and how the revision’s instructions correspond to the CASA AD’s equivalent requirements. Retain the FAA approval documentation with the maintenance records demonstrating compliance.

Following these steps will align operator actions with the requirements stated in AD/B747/369 as reproduced. Because the Directive references specific SBs and FAA AD material, compliance depends on careful engagement with those technical documents and proactive management of inspection schedules and parts logistics. The “before further flight” condition is the most operationally significant constraint; operators should plan inspections and parts provisioning so that aircraft are not unduly grounded when corrective actions are required.