AD/B727/219 - Auxiliary Fuel Tanks

The directive rests on a compact set of regulatory concepts and operational controls, expressed in the AD headings and Appendix A. The primary legal mechanism is a mandatory deactivation requirement tied to CASA approval. The AD identifies the population of affected aircraft precisely by model and STC: "Model 727‑281 aeroplanes equipped with auxiliary fuel tanks installed in accordance with United States Federal Aviation Administration (FAA) Supplemental Type Certificate (STC) SA3449NM" (Applicability). That tight applicability confines the requirement to a defined STC installation rather than all 727s or all auxiliary tanks generally.

Approval and delegated decision making are central. The operator must submit a deactivation procedure "approved by: Manager, Continuing Airworthiness, Airworthiness and Engineering Branch, Civil Aviation Safety Authority" and the AD provides the mailing and facsimile addresses for that submission (Requirement). Note 1 of the AD explicitly links administrative timing to procedural approval: "Timely approval is dependent on early submittal of the deactivation procedures." This places an onus on operators to draft and submit a technically complete procedure early if they are to meet the 90‑day compliance window.

The AD distinguishes between deactivation and physical removal. It allows residual auxiliary tank components to remain provided they are "secured and must have no effect on the continued operational safety and airworthiness of the aeroplane" (Requirement). However, the Appendix includes steps that may amount to partial removal in practice, for example "removing the bladder might help eliminate out‑gassing" (Appendix A, para 1, Note). This creates a conditional technical continuum from simple isolation to partial dismantling, to be defined by the approved procedure.

Documentation and continuing airworthiness are integrated into the remedy. Appendix A mandates AFM amendment (including removal of STC supplement AFM procedures and a placard in the flight deck), maintenance manual amendments, and possible weight and balance revisions with CASA approval where required (Appendix A, paras 6-8). The directive therefore operates not only at the hardware level but also through the aircraft’s operational and maintenance documentation.

Safety verification closes the loop. Appendix A requires post‑deactivation leak and pressure checks and explicit verification that the aeroplane’s fuel quantity indication system (FQIS) and fuel distribution systems have not been adversely affected (Appendix A, para 9). The AD therefore couples a preventive hardware isolation with checks intended to detect unintended impacts on OEM systems.

Interoperability with FAA material is explicit. The AD points to FAA AD 2009‑20‑01 and notes FAA Advisory Circular AC 25‑8 as an example of an "approved method" for capping and securing disconnected fuel plumbing interfaces (Requirement; Appendix A, para 4). That reference ties the CASA approval process to at least one existing FAA standard, while leaving final approval to the CASA Manager, Continuing Airworthiness.

Incentive structure and constraints derive from the combination of a short compliance window, CASA approval required, and the mandate that deactivation must not create additional continued airworthiness instructions. Operators therefore face trade‑offs: they must act quickly to remove a safety risk, but their remedial steps must not themselves add ongoing maintenance or operational burdens requiring new instructions.

The directive names its target population narrowly and also identifies secondary stakeholders by the actions required. Directly affected parties are operators and registrants of Boeing Model 727‑281 aircraft fitted with Rogerson STC SA3449NM auxiliary fuel tanks, because the Applicability provision limits the rule to that model/STC combination. These operators must prepare and submit deactivation procedures to CASA and must perform the deactivation within 90 days of the effective date (Compliance; Requirement).

Maintenance organisations and engineers who perform continuing airworthiness tasks are directly implicated. Appendix A requires physical disconnection and capping of electrical, pneumatic and fuel plumbing interfaces, stowage or securement of components, pulling and collaring circuit breakers, performance of leak/pressure checks and post‑work verification of FQIS and fuel distribution systems (Appendix A, paras 1-5, 9). Those tasks fall within the competence and workload of appropriately approved maintenance organisations and certificated maintenance personnel.

Flight operations staff and pilots are affected through mandatory documentation changes. Appendix A requires AFM amendments that remove the auxiliary tank operating procedures and indicate that the STC AFM Supplement is not in effect, and it requires a placard in the flight deck noting the auxiliary tank is deactivated (Appendix A, para 7). These steps change the operational information available to flight crew and may alter dispatch or operational limitations.

Organisational compliance roles are implicated. The operator must assess whether weight and balance revisions are required and "obtain CASA approval" if so (Appendix A, para 6). That assigns a decision role to both the operator (to detect and propose any weight and balance changes) and to CASA (to approve proposed revisions). It also identifies CASA’s Manager, Continuing Airworthiness as the central decision maker for approving deactivation procedures (Requirement).

Third parties referenced by the directive include the STC holder and Rogerson Aircraft Corporation, whose technical contact details are given for technical information (Note 2). The AD’s Note 3 and FAA cross references bring FAA regulatory materials into scope for those preparing the procedure: FAA AD 2009‑20‑01 is explicitly referred to (Note 3) and FAA Advisory Circular AC 25‑8 is cited in Appendix A as "one approved method" for securing disconnected fuel plumbing interfaces (Appendix A, para 4). That means engineers preparing the procedure will likely consult FAA material in addition to complying with CASA’s approval requirements.

Who pays: the text places no monetary grants or subsidies; the operator must implement the deactivation procedures, amend documentation and perform tests. Those tasks imply direct cost and downtime borne by the operator and the maintenance organisation engaged to implement the work. The AD does not allocate costs or compensation to the STC holder or to CASA; all procedural submissions are to CASA for approval.

Who decides and exercises discretion: CASA’s Manager, Continuing Airworthiness has approval authority for the deactivation procedures, creating a centralised point of discretion over whether a proposed procedure meets the AD’s criteria (Requirement). Note 1 warns that "Timely approval is dependent on early submittal of the deactivation procedures," signalling that CASA controls the calendaring and therefore the operator’s ability to meet the 90‑day deadline.

Finally, airlines or operators that have removed or never installed the Rogerson STC auxiliary tanks are outside the applicability and therefore not affected by these directives, as the AD’s Applicability field is specific.

The AD imposes a set of concrete duties on operators and prescribes certain options and procedural rights. Duties that the AD imposes and their textual bases are as follows.

• Duty to deactivate: Operators must "Deactivate the auxiliary fuel tanks, in accordance with a procedure approved by: Manager, Continuing Airworthiness, Airworthiness and Engineering Branch, Civil Aviation Safety Authority" (Requirement). This is the central obligation.

• Duty to secure residual components: If components remain after deactivation they "must be secured and must have no effect on the continued operational safety and airworthiness of the aeroplane" (Requirement).

• Duty to avoid creating new continuing airworthiness instructions: "Deactivation may not result in the need for additional instructions for continued airworthiness" (Requirement). This constrains remedial options that would introduce new ongoing maintenance obligations.

• Duty to meet the compliance timeline: The operator must complete deactivation "Within 90 days after the effective date of this Directive" (Compliance).

• Duty to include specific technical actions where applicable: Appendix A lists actions the approved procedure "might need to address," including draining and vapour clearing, disconnecting electrical and pneumatic connections, capping feed and vent plumbing, leaving vent lines open and secured to avoid structural deformation, pulling and collaring circuit breakers, and conducting leak/pressure checks and FQIS verification (Appendix A, paras 1-5, 9).

• Duty to amend documentation: Operators must revise weight and balance if required and "obtain CASA approval" (Appendix A, para 6), "Amend the applicable sections of the applicable aircraft flight manual (AFM)" to remove auxiliary tank operating procedures and indicate that the STC AFM supplement is not in effect, and to place a placard in the flight deck; also amend the maintenance manual to remove auxiliary tank maintenance procedures (Appendix A, paras 7-8).

• Duty to provide operator‑specific steps: Appendix A requires that operators "Include with the operator's proposed procedures any relevant information or additional steps that are deemed necessary by the operator to comply with the deactivation and return the aeroplane to service" (Appendix A, para 10). That makes the operator responsible not only for following the Appendix guidance but for proposing any additional steps needed.

Rights, choices and permitted methods:

• Right to propose a deactivation procedure and seek CASA approval: The AD requires a CASA‑approved procedure but does not prescribe a single mandated method; it instructs operators to submit their proposed procedures for approval (Requirement; Appendix A, para 10).

• Use of FAA guidance as one approved method: The AD notes that "one approved method is specified in FAA Advisory Circular AC 25‑8 Auxiliary Fuel Tank Systems Installations" for securing disconnected auxiliary fuel tank plumbing interfaces; appended language therefore allows use of that FAA method as a permissible approach subject to CASA approval (Appendix A, para 4).

• Procedural option for AFM update: The AD states the AFM revisions "may be accomplished by inserting a copy of this AD into the AFM" (Appendix A, para 7). That is an authorised, administratively light option for complying with AFM amendment duties.

• Right to technical assistance: The AD supplies a named technical contact at Rogerson Aircraft Corporation for technical information (Note 2), which operators may consult while preparing a CASA‑approved procedure.

Roles of CASA and Manager, Continuing Airworthiness:

• CASA’s Manager, Continuing Airworthiness is the approval authority. The AD supplies the specific address and facsimile for submission and expects CASA to review and approve the procedure before deactivation is completed (Requirement).

• Note 1 places an operational constraint on both parties, advising that "Timely approval is dependent on early submittal of the deactivation procedures." This implicitly grants CASA discretion to manage approvals within timeframes that depend on operator submission timing.

Constraints and limits:

• The AD explicitly prevents the deactivation from creating new continuing airworthiness instructions; an operator proposing a procedure that would create ongoing maintenance needs may therefore be refused or required to alter its proposal (Requirement).

• The AD requires verification that OEM systems like the FQIS and fuel distribution have not been adversely affected (Appendix A, para 9), which limits the types of isolation/securing measures that are acceptable.

Overall, the duties require operators to prepare and implement a technically detailed plan, secure remaining hardware so it does not affect safety, update documentation, and obtain CASA approval. The AD grants the operator the right to propose the procedure and to use FAA AC 25‑8 as one possible method, subject to CASA approval.

The text of the AD sets out mandatory actions and a compliance period, but it does not itself specify penalties, fines or criminal sanctions within the printed material. The directive requires deactivation "Within 90 days after the effective date of this Directive" and prescribes the approval pathway and technical criteria, but it contains no express enforcement clause or statutory penalty schedule in the body of the document provided.

Enforcement mechanisms implicit in the AD structure are procedural and administrative rather than detailed as monetary or criminal sanctions in the text. The directive stipulates that the deactivation procedure must be "approved by: Manager, Continuing Airworthiness" (Requirement) and provides submission contact details. That creates an administrative compliance pathway: operators must secure CASA approval and complete the listed steps; failure to obtain approval or to carry out the deactivation as required will leave the operator without compliance certification under this AD text.

The AD gives specific process elements that CASA can use as objective benchmarks when assessing compliance: physical disconnection and capping of plumbing, securement of residual components, pulling and collaring circuit breakers, AFM and maintenance manual amendments, leak/pressure checks and verification that the aeroplane FQIS and fuel distribution systems have not been adversely affected (Appendix A, paras 1-5, 7-9). Those items provide concrete inspection and audit points for CASA or its authorised inspectors when determining whether the required deactivation has been completed to the standards specified.

Note 1 emphasises timing for approval , "Timely approval is dependent on early submittal of the deactivation procedures" , which creates a compliance‑risk dynamic: operators who delay submission may miss the 90‑day window through no immediate fault of CASA, or alternately their late submission may be rejected or require extension; the AD does not spell out extension mechanisms or grace periods.

Because the directive provides contact and approval addresses, CASA is positioned to accept, review and approve proposed procedures and to request further information; the AD does not articulate an appeal or review process for CASA decisions in the text provided. It also does not state whether failure to comply would be treated as rendering the aeroplane unairworthy, nor does it state specific sanctions. Practitioners should therefore note the absence of penalty provisions in the AD text itself and take remedial action in line with CASA practice and broader aviation safety regulation, recognising that the AD expresses a mandatory safety requirement.

For technical implementation and coordination the AD supplies a Rogerson technical contact (Note 2), and it cross‑refers FAA AD 2009‑20‑01 (Note 3). Those references provide both technical avenues for resolution and cross‑jurisdictional material that CASA may use when enforcing compliance, but the AD text itself leaves enforcement specifics to CASA’s administrative processes rather than setting out statutory penalties.

The directive references and incorporates external aviation regulatory materials and operational documentation in ways that create interdependencies between this AD and other regulatory or technical instruments.

Cross‑jurisdictional FAA materials: The AD explicitly references FAA regulatory and guidance materials. Note 3 reads "FAA AD 2009‑20‑01 Amdt 39‑16024 refers," and Appendix A states that for capping disconnected auxiliary fuel tank plumbing interfaces "one approved method is specified in FAA Advisory Circular AC 25‑8 Auxiliary Fuel Tank Systems Installations" (Requirement; Appendix A, para 4). These references make FAA material relevant to the CASA approval process for deactivation procedures. The AD does not adopt FAA materials wholesale; rather it recognises them as relevant examples or background documents that operators may use when developing their CASA‑approved procedure.

Interaction with the aircraft’s operational and maintenance documentation: Appendix A requires amendments to the AFM and maintenance manual and may require revisions to the weight and balance document with CASA approval (Appendix A, paras 6-8). Those kinds of document changes ordinarily interact with separate regulatory regimes governing continuing airworthiness records and flight operations documentation. The AD instructs that AFM revisions may be accomplished by inserting a copy of the AD into the AFM, which creates a direct, minimal administrative interaction between the AD and AFM requirements (Appendix A, para 7).

Effect on OEM systems and systems certification: Appendix A requires verification that the FQIS and fuel distribution systems have not been adversely affected by deactivation actions (para 9). That requirement creates an interface between the corrective action for the STC‑installed auxiliary tanks and the OEM systems’ continuing airworthiness and certification considerations. The AD also instructs that deactivation "may not result in the need for additional instructions for continued airworthiness" (Requirement), limiting the operator’s ability to introduce new ongoing instructions that would themselves interact with continuing airworthiness regulation.

Approval and administrative law interface: The deactivation procedure must be "approved by: Manager, Continuing Airworthiness … CASA" (Requirement). That approval requirement puts the AD squarely into the administrative law frame: CASA has approval authority and discretion, and its decisions on approval will be governed by CASA’s internal policies and aviation regulatory frameworks. The AD itself does not set out the substantive approval criteria beyond the technical actions required in Appendix A, but the approval function will involve CASA’s internal processes and standards.

Interaction with STC documentation and the STC holder: The AD targets Rogerson STC SA3449NM installations and provides Rogerson contact information for technical information (Note 2). Consequently, there's an interaction between the STC holder’s technical data and the operator's CASA‑submitted procedure. The AD also requires that the AFM Supplement for the STC be indicated as not in effect (Appendix A, para 7), which interacts with STC‑specific AFM material.

Operational safety laws and certification regimes: While the AD does not itself restate broader aviation safety statutes, its mandatory deactivation requirement operates within the wider regulatory framework that governs airworthiness directives, AFM content, maintenance manuals, and weight and balance documentation. Those other regimes, while not quoted verbatim in the AD, will be implicated when CASA reviews procedures and verifies compliance.

Limitations and non‑adoption: The AD expressly rejects making deactivation create further continuing airworthiness instructions (Requirement). That limit restricts interaction with ongoing maintenance obligations and prevents the AD from being interpreted as authorising deactivation pathways that would expand continuing airworthiness duties.

In sum, the AD creates a narrow but concrete intersection with FAA advisory and mandatory material, the operator’s AFM and maintenance manuals, weight and balance approval processes, and CASA administrative approval procedures. The AD does not itself amend statutes or specify penalties; rather it operates through procedural approvals and documentation updates that interact with existing aviation safety regulatory frameworks.

The document provided constitutes AD/B727/219 issued in 12/2009. Chronological facts present in the directive are:

• Issuance and signatory date: The AD is dated and signed by James Coyne, Delegate of the Civil Aviation Safety Authority, with a printed date of 30 September 2009 at the end of the body text.

• Publication and effective date: The AD includes a statement that "This Airworthiness Directive becomes effective on 19 November 2009" (Compliance).

• Compliance window: The AD sets a compliance period of "Within 90 days after the effective date of this Directive" (Compliance).

• Cross references to FAA action: The AD refers to FAA AD 2009‑20‑01 Amdt 39‑16024 in Note 3, indicating contemporaneous FAA action relevant to the subject.

• AD identification: The header includes the AD identification "AD/B727/219" and the title "Auxiliary Fuel Tanks 12/2009" which situates this AD in CASA’s AD series and the 12/2009 bulletin.

No textual amendments, revisions, supersessions, or subsequent amendment entries are included in the material supplied. There is no separate amendment log or history beyond the issuance date, effective date and the compliance timeline contained within the text. The Appendix A deactivation criteria are presented as part of the AD as issued and no later changes or insertions are shown in the provided document.

If a practitioner needs to know whether this AD was subsequently amended, superseded, or withdrawn after the effective date, that information is not present in the supplied text. The supplied AD does, however, reference FAA AD 2009‑20‑01 as a related piece of regulatory action, which may be relevant when tracing parallel amendment history in another jurisdiction.

The text provided contains no litigation history, case citations, or references to judicial review or administrative appeals arising from AD/B727/219. The AD makes technical and administrative mandates but does not include any record of court proceedings, enforcement adjudications, or legal challenges in the document supplied.

Absence of litigation references in the AD does not itself indicate the presence or absence of any legal disputes; it merely records that the directive as issued does not enumerate litigation, nor does it cite cases or decisions. Practitioners seeking case law on the subject, challenges to CASA ADs, or disputes concerning STC installations or deactivation procedures will find no pointers in this AD text and will need to consult external databases, tribunal records or CASA enforcement case files for any post‑issuance litigation or appeals.

For purposes of legal research based solely on the supplied directive, the following are concrete observations from the text:

• No court or tribunal is named in connection with this AD. The AD is an administrative instrument issued by CASA and signed by a CASA delegate (James Coyne), but the document does not discuss or reference appeals, reviews or litigation avenues.

• No enforcement actions, notices of infringement, or penalty determinations appear in the AD text. The directive specifies required technical and documentation steps and an approval pathway but omits procedural remedies or sanctions in its wording.

• The only external instruments explicitly mentioned are FAA materials (FAA AD 2009‑20‑01 and FAA Advisory Circular AC 25‑8). These are regulatory and guidance documents rather than judicial decisions.

Because the AD does not supply litigation history, practitioners requiring knowledge of any legal disputes that may have followed issuance should treat the AD as a technical regulatory instrument and source jurisdictional or legal challenge information outside the AD text itself.

The AD text contains a number of technical and administrative traps that practitioners and operators should watch for; these arise directly from the wording and structure of the instrument.

1. Short compliance window tied to approval timing. The AD requires deactivation "Within 90 days after the effective date of this Directive" (Compliance) and warns that "Timely approval is dependent on early submittal of the deactivation procedures" (Note 1). Operators who wait to assemble a procedure risk missing the 90‑day window because CASA approval is a precondition for the deactivation procedure. Early submission is therefore operationally critical.

2. CASA approval is mandatory and discretionary. The deactivation procedure must be "approved by: Manager, Continuing Airworthiness … CASA" (Requirement). The AD does not prescribe fixed technical acceptance criteria beyond Appendix A, so CASA retains approval discretion; operators cannot unilaterally choose a method and later notify CASA.

3. Deactivation must not create new continuing airworthiness instructions. The Requirement states "Deactivation may not result in the need for additional instructions for continued airworthiness." That limits acceptable remedial measures; a proposed method that creates ongoing maintenance burdens may be disallowed even if it achieves isolation of the auxiliary tank.

4. Residual components cannot affect safety. The AD permits residual components to remain only if they "must be secured and must have no effect on the continued operational safety and airworthiness of the aeroplane" (Requirement). That is a strict factual test that will require evidence or demonstration at approval and on inspection.

5. Vent line handling nuance. Appendix A instructs that "In order to eliminate the possibility of structural deformation during cabin decompression, leave open and secure the disconnected auxiliary fuel tank vent lines." Operators accustomed to capping lines may need to follow a specific approach for vent lines to avoid structural issues.

6. Weight and balance approval requirement. Appendix A requires revision of weight and balance "if required, and obtain CASA approval" (para 6). Operators must identify whether deactivation creates a weight and balance change and cannot simply file a local amendment without CASA sign‑off.

7. AFM amendment technique and placarding. The AD permits AFM revision by inserting a copy of the AD into the AFM (Appendix A, para 7), which is an administratively light route. However, operators must also "Remove auxiliary fuel tank operating procedures" and "Amend the Limitations Section of the AFM to indicate that the AFM Supplement for the STC is not in effect" (Appendix A, para 7). Simple insertion may not satisfy the substantive removal requirement if the language of procedures remains in other documents.

8. Technical verification obligations. Appendix A requires "procedures such as leak checks and pressure checks deemed necessary before returning the aeroplane to service" and explicit verification "that the aeroplane FQIS and fuel distribution systems have not been adversely affected" (para 9). These are specific test obligations; failure to conduct or document them will raise compliance questions.

9. Use of FAA guidance is optional but not exclusive. Appendix A notes that FAA Advisory Circular AC 25‑8 is "one approved method" for capping plumbing interfaces (para 4). Operators should not assume that following AC 25‑8 guarantees CASA approval without prior discussion, but the AC provides a known method to propose.

10. Technical contact logistics. The AD provides Rogerson Aircraft Corporation contact details with international dialling prefixes (Note 2). Practically, operators will need to allow for time differences and international communication when seeking Rogerson technical input.

11. Deactivation may be implemented in stages. The AD permits retention of some components if secured, yet the Appendix suggests more extensive actions (e.g., removing the bladder "might help eliminate out‑gassing") (Appendix A, para 1, Note). Operators and maintainers should not assume that a minimal isolation will be sufficient; CASA approval will require demonstration that any retained parts pose no vapour or ignition risk.

12. No penalties specified in the AD text. The AD does not detail enforcement penalties or appeal processes. That absence is itself a risk: operators must comply on the AD’s technical terms and cannot rely on the AD text for guidance on enforcement or recourse if CASA rejects a proposed procedure.

These are concrete operational and administrative pitfalls that flow from the AD’s wording. Each creates an implementation decision point where operators should document choices, seek CASA pre‑approval where possible, and maintain records showing compliance with the Appendix A verification steps.

This section sets out a compliance checklist and a recommended sequencing of steps strictly grounded in the directive text and Appendix A. All items below are derived from the AD’s Requirement and Appendix A and must be completed within the AD’s compliance period ("Within 90 days after the effective date of this Directive").

1. Confirm applicability. Verify that the aeroplane is a Boeing Model 727‑281 fitted with auxiliary fuel tanks installed under FAA STC SA3449NM. The AD applies only to that model/STC combination (Applicability).

2. Prepare a deactivation procedure. Draft a deactivation procedure that addresses the Appendix A items and any operator‑specific actions deemed necessary. Appendix A states operators should "Include with the operator's proposed procedures any relevant information or additional steps that are deemed necessary by the operator to comply with the deactivation and return the aeroplane to service" (Appendix A, para 10).

3. Early submission to CASA. Submit the proposed deactivation procedure to the Manager, Continuing Airworthiness, Airworthiness and Engineering Branch, CASA at GPO Box 2005 Canberra ACT 2600 or facsimile 07 3144 7388, because "Timely approval is dependent on early submittal of the deactivation procedures" (Note 1). Early submission is necessary to secure approval and meet the 90‑day deadline.

4. Include the Appendix A technical actions in the procedure:

   • Permanently drain auxiliary fuel tanks and clear them of fuel vapours to eliminate out‑gassing (Appendix A, para 1). Consider removal of the bladder where applicable ("removing the bladder might help eliminate out‑gassing") (Appendix A, para 1, Note).
   • Disconnect all electrical connections related to the auxiliary tank, including FQIS wiring, fuel pump wiring, float switches and any other auxiliary tank electrical connections, and stow them at the auxiliary tank interface (Appendix A, para 2).
   • Disconnect pneumatic connections where applicable, cap them at the pneumatic source, and secure them (Appendix A, para 3).
   • Disconnect fuel feed and vent plumbing interfaces with OEM tanks, cap them at the aeroplane tank side, and secure them in accordance with an approved method; Appendix A notes "one approved method is specified in FAA Advisory Circular AC 25‑8" (Appendix A, para 4). For vent lines, Appendix A instructs leaving disconnected auxiliary fuel tank vent lines open and secured to avoid structural deformation during cabin decompression.
   • Pull and collar all circuit breakers used to operate the auxiliary tank (Appendix A, para 5).

5. Documentation updates:

   • Revise weight and balance records if required and "obtain CASA approval" for any such revision (Appendix A, para 6).
   • Amend applicable sections of the AFM to indicate the auxiliary tank is deactivated, remove auxiliary tank operating procedures so only OEM fuel procedures remain, and amend the Limitations Section to indicate the AFM Supplement for the STC is not in effect. The AD notes these AFM revisions "may be accomplished by inserting a copy of this AD into the AFM" (Appendix A, para 7).
   • Place a placard in the flight deck indicating the auxiliary tank is deactivated (Appendix A, para 7).
   • Amend applicable sections of the aeroplane maintenance manual to remove auxiliary tank maintenance procedures (Appendix A, para 8).

6. Testing and verification before return to service:

   • Perform leak checks and pressure checks or other procedures deemed necessary before returning the aeroplane to service (Appendix A, para 9).
   • Verify that the aeroplane FQIS and fuel distribution systems have not been adversely affected by deactivation activities (Appendix A, para 9).

7. Secure residual components. Ensure any auxiliary tank components left on the aeroplane are secured and demonstrably have no effect on continued operational safety and airworthiness (Requirement).

8. Maintain evidence and records. Compile documentation of the completed physical actions, AFM and maintenance manual amendments (or AD insertion), weight and balance approvals, circuit breaker collaring, and test results demonstrating FQIS and fuel distribution system integrity. These records will be necessary to show compliance with the AD and to support CASA approval if follow up verification is required.

9. Liaise with Rogerson for technical information if necessary. The AD provides a named technical contact at Rogerson Aircraft Corporation (Dan Zevallos) and full contact details (Note 2), which operators may use to obtain STC‑specific technical guidance while preparing the CASA‑approved procedure.

10. Use FAA AC 25‑8 where appropriate. For capping and securing disconnected fuel plumbing interfaces, include in the proposed procedure whether the method specified in FAA Advisory Circular AC 25‑8 will be used, noting the AD identifies AC 25‑8 as "one approved method" (Appendix A, para 4).

11. Submit final procedure and obtain CASA approval. Once the procedure is drafted and internal technical and documentation changes are ready, submit the material to CASA and obtain the Manager, Continuing Airworthiness’s approval before or concurrent with carrying out the deactivation (Requirement). Keep in mind Note 1’s warning that approval timing depends on early submittal.

12. Complete deactivation within the 90‑day window. Schedule maintenance resources, hangar time and documentation updates so that the full deactivation, associated tests and CASA approvals are completed "Within 90 days after the effective date of this Directive" (Compliance).

13. Return to service only after verification. Before returning the aeroplane to service, confirm that leak and pressure checks are completed and that FQIS and fuel distribution system verifications are documented (Appendix A, para 9).

Following the steps above, strictly drawn from the AD and Appendix A, implements the directive’s technical and administrative obligations. The AD provides the CASA approval address and facsimile and identifies Rogerson’s technical contact. Operators should rely on early submission to CASA to secure timely approval as the AD explicitly connects approval timing to early submittal (Note 1).