AD/750XL/9 Amdt 1 - S-Tec X 55 Autopilot System – Disconnect

The Directive uses standard airworthiness-directive mechanics: narrow applicability, immediate risk-mitigation, parts inspection or replacement, functional testing, and a subsequent modification with a specified time-in-service window. Important concepts and operative features in the text are as follows.

Applicability. The Directive is tightly drawn by aircraft model and serial number. It applies to Model PAC 750XL aircraft, serial numbers 125, 126 and 127. The Directive does not purport to apply beyond those serial numbers in the text provided.

Temporary mitigant. Requirement 1 is an immediate, temporary mitigant: the autopilot must be disabled and labelled to prevent its use pending corrective action. The Directive specifies the physical means to accomplish the temporary disablement, for example by pulling and collaring the autopilot circuit breaker and permitting the use of a cable tie. The Directive states the placard wording in the Requirement text. The Directive also clarifies this is temporary until Requirement 2 is done (Note 1).

Identification and replacement of part. Requirement 2 focuses on the pitch servo identification plate and a specific part number: P/N 108-15-P1. The Directive requires inspection of the identification plate; if the P/N is not 108-15-P1, the pitch servo must be replaced with P/N 108-15-P1, following instruction 2.C. in PAC Mandatory SB PACSB/XL/025 dated 5 March 2007. Note 2 identifies an authorised S-Tec dealer as a supply source for the replacement unit.

Reinstatement procedure and verification. Requirement 3 prescribes the steps to reconnect and return the autopilot to service: remove the cable tie, reset the circuit breaker, perform a functional check of the autopilot system, and remove the placard. The Directive therefore separates the safety action (disconnection) from the verification and reinstatement event.

Mandatory modification. Requirement 4 mandates modification of the autopilot system per paragraph 2.B of SB PACSB/XL/025 and PAC Drawing 11-81639 Issue C. The Directive prescribes a time-in-service compliance window for this modification , within the next 150 hours time in service after the effective date of the Amendment.

Cross-references to other technical instruments. The Directive refers to PAC Alert Service Bulletin PACASB/XL/001 dated 16 February 2007, PAC Mandatory Service Bulletin PACSB/XL/025 dated 5 March 2007, and PAC Drawing 11-81639 Issue C. It also states that CAA(NZ) AD DAC/750XL/12A refers (Note 3). These cross-references indicate that the detailed technical steps and drawings are external to the Directive and must be followed as specified.

Safety rationale. The Directive states the original issue was motivated by prevention of Autopilot System Computer failure that could lead to an out-of-trim condition and loss of aircraft control. The Amendment introduces measures to return the autopilot to service and to clarify disconnect/placard placement.

Temporal sequencing and conditionality. The Directive explicitly sequences the temporary disablement, inspection/replacement, functional check/reinstatement and longer-term modification. The text makes Requirement 1 a stop-gap until the servo replacement (Req 2) is done, and links Requirements 2 and 3 to the return-to-service condition, while Requirement 4 is a phased modification within 150 hours. The Directive therefore combines an immediate operational restriction with a technical remediation and a timed modification.

Authority and signature. The Directive is issued under the Civil Aviation Safety Authority, evidenced by the signature block for Charles Lenarcic, Delegate of the Civil Aviation Safety Authority, dated 30 March 2007. The Amendment is noted as becoming effective on 2 April 2007.

Terminology. The Directive uses aviation maintenance and airworthiness terminology: "autopilot circuit breaker", "collaring", "placard", "pitch servo identification plate", "part number P/N 108-15-P1", "functional check", "modify the autopilot system", and "time in service". The material indicates that the technical activities are to be done in accordance with the referenced manufacturer service bulletins and drawings.

The Directive identifies a narrow set of affected stakeholders directly. The primary parties who must act under the Directive are the registered owners, operators, and maintenance providers responsible for Model PAC 750XL aircraft with serial numbers 125, 126 and 127. The Directive’s actions create obligations for those operators and maintenance organisations because they need to implement the required disconnect, inspection/replacement, functional checks and modifications within the specified timelines.

Maintenance suppliers and parts dealers are implicated. Note 2 states that replacement pitch servos P/N 108-15-P1 can be sourced from an authorised S-Tec dealer, which imposes a sourcing channel for replacement parts. This directs operators to a particular vendor network for the required component.

Pilots and flight crews will face an operational constraint while the autopilot is disconnected under Requirement 1. The Directive requires the autopilot to be labelled “DO NOT USE” and the autopilot circuit breaker to be collaring-pulled to prevent re-engagement, which alters in-service operational capability for the specific serial-numbered aircraft until the inspection/replacement and checks are completed. Requirement 1 must be done before further flight after 4 April 2007.

Regulators and safety authorities. The Civil Aviation Safety Authority exercises the authority to issue airworthiness directives. The Directive is signed by a CASA Delegate, indicating administrative decision-making and enforcement context. The Directive also references CAA(NZ) AD DAC/750XL/12A, indicating cross-jurisdictional relevance for New Zealand’s civil aviation authority in relation to the same issue.

Design and engineering resources. The modification in Requirement 4 requires reference to paragraph 2.B. of SB PACSB/XL/025 and PAC Drawing 11-81639 Issue C. That implicates design, engineering, and technical documentation resources. Maintenance organisations will need access to the specified drawings and service bulletin content to perform the modification in conformity with the Directive.

Third-party service providers. If operators do not have in-house maintenance competence, contracted maintenance organisations will perform the inspection, replacement and modification tasks. The Directive’s requirement to source parts from an authorised S-Tec dealer can increase reliance on authorised suppliers and potentially concentrate maintenance economic activity among authorised repair vendors.

Insurance and operational planning. The Directive’s immediate operational effect for the specific airframes means operators must plan around any temporary removal of autopilot capability and the time needed to obtain parts and perform the required modifications and checks. That affects flight scheduling, crew planning and potential revenue for aircraft used in commercial operations, though the Directive itself does not quantify these impacts.

Owners of other 750XL serial numbers are not covered by the text provided. The Directive’s strict serial-number applicability limits direct regulatory obligation to the listed aircraft; owners/operators of other serial numbers may nevertheless be affected indirectly if manufacturer service bulletins recommend similar action or further ADs follow, but that is not stated in the provided text.

The Directive imposes discrete duties on affected operators and maintenance organisations. The duties and procedural rights in the text are as follows.

Duties:

• Immediate disconnection and labelling. Requirement 1 obliges the operator to pull and collar the autopilot circuit breaker to prevent re-engagement, with the option to use a cable tie, and to install a placard in clear view of the pilot on or adjacent to the autopilot controller with the Directive’s specified wording. This must be completed before further flight after 4 April 2007. The Directive clarifies this is temporary until Requirement 2 is achieved (Note 1). The exact placard text is given in the Requirement: "DO NOT USEPacific Aerospace Limited (PAC) 750XL Alert Service Bulletin (SB) PACASB/XL/001 dated 16 February 2007 refers." The placement is specified as "in clear view of the pilot on or adjacent to the autopilot controller."

• Part inspection and replacement. Requirement 2 requires inspection of the pitch servo identification plate and confirmation that the pitch servo P/N is 108-15-P1. If the part number is not 108-15-P1, the operator must replace the pitch servo with P/N 108-15-P1 in accordance with instruction 2.C. of PACSB/XL/025 dated 5 March 2007. Note 2 identifies that replacement P/N 108-15-P1 servos can be sourced from an authorised S-Tec dealer.

• Functional check and restoration. Requirement 3 requires removal of the cable tie, resetting the circuit breaker, performing a functional check on the autopilot system and removing the “DO NOT USE” placard before returning the autopilot to service. The Directive links completion of Requirements 2 and 3 to the condition "before returning the autopilot system to service."

• Modification per drawings and SB. Requirement 4 compels modification of the autopilot system in accordance with paragraph 2.B. of SB PACSB/XL/025 and PAC Drawing 11-81639 Issue C. This modification must be completed within 150 hours time in service after the effective date of the Amendment.

Rights and conditionalities:

• Sequencing flexibility limited by deadlines. The Directive recognises sequencing: Requirement 1 is temporary until Requirement 2 is completed. The duty to restore the autopilot requires that Requirements 2 and 3 be done; the Directive does not otherwise allow use of the autopilot without compliance. The Directive allows the use of a cable tie as one means of collaring the circuit breaker, which is a procedural flexibility specified in the Requirement.

• Reliance on referenced SB for procedures. The Directive delegates detailed procedure to manufacturer-issued service bulletins and drawings. Requirement 2 references instruction 2.C. of SB PACSB/XL/025 dated 5 March 2007 for the replacement procedure, and Requirement 4 references paragraph 2.B. of the same SB and PAC Drawing 11-81639 Issue C for system modification. The Directive therefore incorporates those technical instructions by reference, creating a constrained right: the operator must follow the SB and drawings for the technical remedy.

• Sourcing channel for replacement component. Note 2 identifies an authorised S-Tec dealer as a source for the replacement pitch servo P/N 108-15-P1. That is not framed as an exclusive supplier requirement in statutory terms within the Directive text, but it is an explicit sourcing instruction in the Note.

Unstated enforcement detail. The Directive specifies what must be done and when, but it does not include statutory penalty language within the text supplied. The Directive is signed by the CASA Delegate and contains explicit compliance dates; these features typically signal enforceability under airworthiness and regulatory regimes, but the Directive itself does not specify penalty amounts or procedures within its text.

Documentation and traceability. The Directive requires inspectors and maintainers to check identifying plates and perform part replacement and functional testing. Implicitly, this creates a record-keeping need because returning the autopilot to service is conditioned on completion of Requirements 2 and 3. The Directive does not specify the form or retention period for records in the text provided.

Cross-reference obligations. The Directive binds operators to comply with related service material. The duty to modify per the specified paragraph and drawing makes compliance contingent on obtaining and following those documents.

The Directive text, as provided, does not specify penalties, fines or a detailed enforcement regime. It records compliance requirements, specified deadlines, and the issuing authority, but it does not include an express sanctions clause in the body of the text supplied.

What the Directive does provide that is pertinent to enforcement:

• Compliance deadlines and conditions. The Directive prescribes definitive compliance timings: Requirement 1 must be completed "Before further flight after 4 April 2007"; Requirements 2 and 3 must be completed "Before returning the autopilot system to service"; Requirement 4 must be completed "Within the next 150 hours time in service after the effective date of this Amendment." These time-critical instructions frame the regulatory expectation of action by operators and maintainers.

• Issuing authority. The document is signed by Charles Lenarcic, Delegate of the Civil Aviation Safety Authority, and the Amendment is declared to become effective on 2 April 2007. That identifies the issuing authority responsible for issuing the Directive and indicates the regulatory provenance of the requirement.

• Cross-referenced technical mandates. The Directive makes compliance contingent on specific manufacturer service bulletins and drawings. These references are incorporated by instruction, which is a typical enforcement mechanism in aviation regulation: failure to follow an AD and its referenced SBs is treated as non-compliance with airworthiness directives. The Directive references PACSB/XL/025 and PAC Drawing 11-81639 Issue C for the substantive technical steps.

What the Directive does not state in the supplied text:

• The Directive does not describe any penalty amounts, suspension or revocation procedures, administrative fines, or criminal sanctions. It also does not describe inspection programmes, spot audits or follow-up reporting obligations in this text.

Practical enforcement implications the Directive creates, grounded in the text:

• Operators must either implement the listed measures to comply with the Directive or leave the autopilot in a disabled state. Because Requirement 1 must be completed before further flight after the specified date, operators of the affected serial-number aircraft must take immediate action to maintain airworthiness in the sense of complying with the Directive’s requirements.

• The Directive’s cross-reference to manufacturer SBs and to a New Zealand AD (CAA(NZ) AD DAC/750XL/12A) provides regulators and inspectors with contemporaneous technical instruments they can use to verify compliance. The Directive itself requires inspection of a part identification plate and replacement if it is not the specified P/N. Those are verifiable physical actions.

Absent explicit penalty text, readers must rely on the broader statutory and regulatory framework that enables CASA to enforce airworthiness directives. The Directive as provided gives deadlines, procedures and a clear issuing authority, but it leaves the specific enforcement mechanisms and penalties outside its own text.

The Directive incorporates and refers to external technical and regulatory materials but contains no explicit cross-references to statutory provisions beyond being an instrument of the Civil Aviation Safety Authority. The interactions recorded in the text are limited to the following:

Service bulletins and drawings. The Directive requires work to be carried out "per instruction 2.C. in PAC 750XL Mandatory SB PACSB/XL/025, dated 5 March 2007" (Requirement 2), and to modify the autopilot system "in accordance with paragraph 2.B. of SB PACSB/XL/025 and PAC Drawing 11-81639 Issue C" (Requirement 4). Those references make the Directive operationally dependent on the content of the manufacturer-issued service bulletin and drawing. Practically, compliance requires obtaining and following those documents. The Directive therefore interacts with manufacturer-provided technical material by making compliance contingent on external technical instructions.

Other airworthiness directives. The Directive’s Note 3 states "CAA(NZ) AD DAC/750XL/12A refers." That indicates that a comparable or related airworthiness directive exists under the New Zealand civil aviation authority for the same aircraft type or issue. The text does not further elaborate on the content or requirements of the New Zealand AD, but the cross-reference signals parallel regulatory action in another jurisdiction which may influence operators that are subject to multiple national regulators.

Alert service bulletin reference. Requirement 1’s placard text references "Pacific Aerospace Limited (PAC) 750XL Alert Service Bulletin (SB) PACASB/XL/001 dated 16 February 2007", which means the initial alert bulletin is part of the prescriptive context. The Directive thus links to both an alert SB and a mandatory SB, embedding the AD within the manufacturer’s advisory and mandatory guidance suite.

Airworthiness and regulatory framework. The Directive is an instrument of the Civil Aviation Safety Authority and is signed by a CASA Delegate. While the Directive text does not itself reproduce the enabling legislation, it is an administrative act of an aviation regulator. The Directive’s enforcement and legal effect therefore sit in the broader aviation regulatory framework under which CASA issues ADs, but the Directive text does not quote or reproduce enabling statutory provisions, nor does it specify the interaction with other administrative acts such as certificate suspension or enforcement proceedings.

No explicit interaction with other commercial or contract laws. The Directive does not expressly address contract, tort, insurance, or employment law consequences. It does not provide indemnities, compensation, or procurement instructions beyond noting a source for replacement parts (authorised S-Tec dealer). Any legal effects in those other domains are outside the text provided.

Geographic and jurisdictional nexus. The Directive was issued by CASA and references a CAA(NZ) AD. The Directive therefore operates within both an Australian CASA context and is linked, by reference, to New Zealand authority action. The text does not otherwise address cross-border regulatory harmonisation mechanisms or which jurisdictional rules prevail where both authorities act.

Record-keeping and certification. The Directive requires functional checks and replacement of parts as preconditions to returning the autopilot to service, which implies a need to update maintenance records and perhaps airworthiness records. The Directive does not prescribe the form, but it interacts practically with maintenance certification obligations because returning an aircraft system to service usually requires certified maintenance release; the Directive mandates the work that underpins that certification step.

The supplied text contains an explicit amendment record and dates. The history in the document is limited but concrete:

• Original issue. The original issue of AD/750XL/9 was effective on 12 March 2007. The Directive states that the original issue was intended to prevent failure of the Autopilot System Computer, which could lead to an out-of-trim condition and potentially loss of aircraft control.

• Amendment 1. The cover identifies this document as "AD/750XL/9 Amdt 1" and states "This Amendment becomes effective on 2 April 2007." The document is signed by the CASA Delegate, Charles Lenarcic, and dated 30 March 2007. The Amendment introduces actions which allow the autopilot to be returned to service and clarifies how to disconnect the autopilot and where to install the placard.

• Effective dates and staged compliance. The Amendment sets the effective date and specific compliance deadlines. Requirement 1 must be completed before further flight after 4 April 2007. Requirements 2 and 3 must be completed before returning the autopilot to service. Requirement 4 must be completed within 150 hours time in service after the effective date of the Amendment.

• References to service bulletins. The Amendment specifically references PAC Alert SB PACASB/XL/001 dated 16 February 2007 and PAC Mandatory SB PACSB/XL/025 dated 5 March 2007, and PAC Drawing 11-81639 Issue C. These references indicate that the Amendment both builds on prior manufacturer guidance and incorporates manufacturer procedural instructions.

• Cross-jurisdictional referencing. The Amendment notes that CAA(NZ) AD DAC/750XL/12A refers, indicating concurrent or related regulatory action in New Zealand for the same aircraft type or issue.

No further amendment entries, rescission or superseding directives appear in the supplied text. The Amendment record in the document shows that the original AD was issued quickly and that Amendment 1 followed within weeks to permit return-to-service measures and clarity on disconnect procedures.

The supplied Directive text contains no information about litigation, legal challenges, judicial review, or case history related to AD/750XL/9 or this Amendment. The document does not name or cite any court decisions, does not record any appeals or disputes, and does not describe any legal proceedings. The only legal or quasi-legal instrument present is the Airworthiness Directive itself, issued by the Civil Aviation Safety Authority and signed by the Delegate. The document therefore records no litigation history within the text provided.

Given the absence of litigation references in the source, readers seeking case law or judicial treatment of this specific Directive would need to consult case reports, tribunal records, or administrative appeals external to this document. The Directive alone does not include or summarise any subsequent legal challenge or enforcement action.

The Directive contains several discrete textual and operational features that create potential pitfalls for operators, maintainers and compliance officers. These items are derived strictly from the text and its structure.

Narrow serial-number applicability. The AD applies only to Model PAC 750XL aircraft, serial numbers 125, 126 and 127. Operators of other serial numbers must not assume they are covered or exempt; the Directive does not state that similar aircraft are unaffected. Compliance obligations are therefore specific and non-general. Misreading the serial-number scope could lead to unnecessary interventions on unaffected aircraft or non-compliance on affected aircraft.

Placard wording formatting. The required placard wording is provided verbatim in the Directive: "DO NOT USEPacific Aerospace Limited (PAC) 750XL Alert Service Bulletin (SB) PACASB/XL/001 dated 16 February 2007 refers." The Directive does not add punctuation or formatting to separate "DO NOT USE" and the rest of the sentence. That lack of spacing or punctuation in the printed text could give rise to ambiguity about the intended placard text and where line breaks or punctuation should be. The Directive does not explicitly prescribe punctuation or line breaks, only the words shown, and it also specifies placement "in clear view of the pilot on or adjacent to the autopilot controller." Operators should ensure the placard is legible and placed as directed; literal reproduction of the string without spacing might not be practicable.

Temporary measure conditionality. Requirement 1 is explicitly a temporary measure until Requirement 2 is accomplished (Note 1). That means an operator may not treat Requirement 1 as a long-term mitigation: it is a stop-gap. Returning to autopilot use requires completion of Requirements 2 and 3. If an operator performs Requirement 1 and then delays replacement, they will be operating with a disabled autopilot, likely affecting operational capability.

Sourcing the replacement servo. Note 2 states that a replacement pitch servo P/N 108-15-P1 can be sourced from an authorised S-Tec dealer. The Directive does not designate alternative supply channels or permit used parts; it does not say the replacement must be new, nor does it state mandatory authorisation for installation. However, because the Directive references the mandatory SB for replacement instructions, maintainers will likely need to ensure parts provenance and compatibility. Reliance on an authorised S-Tec dealer may introduce delay and cost, and the Directive does not provide contingencies for parts availability.

Interplay between Requirements 2 and 3. Requirements 2 and 3 are linked by the phrase "Before returning the autopilot system to service." That means an operator may conduct the replacement and then perform the functional check and remove the placard to restore functionality. The Directive does not specify what constitutes an adequate functional check. The required functional check must be performed, but the Directive leaves the technical scope to the referenced SBs and to maintenance practice. Lack of a prescriptive functional checklist within the AD could create variability in what different maintenance organisations consider sufficient.

Timing of Requirement 4. Requirement 4 mandates a modification within 150 hours time in service after the effective date of the Amendment. Operators must track time-in-service carefully from the effective date to ensure the modification is completed within that window. The Directive does not provide an alternative compliance period or extension mechanism in the text supplied. Failure to complete the modification within 150 hours could mean continued vulnerability or potential regulatory non-compliance.

Reliance on external documents. The Directive integrates instructions from SB PACSB/XL/025 and PAC Drawing 11-81639 Issue C. The AD does not reproduce those technical instructions. Operators must obtain those documents and follow them exactly, particularly instruction 2.C. and paragraph 2.B. If a maintenance organisation does not have immediate access to the SBs or the drawing, compliance may be delayed.

No penalties stated. The Directive does not specify penalties within its text. That absence might create uncertainty for those unfamiliar with CASA’s enforcement framework. The operational reality is that failure to comply with an AD typically has regulatory consequences, but the Directive itself does not state them.

Cross-jurisdictional references. Note 3 states "CAA(NZ) AD DAC/750XL/12A refers." Operators operating internationally or registered in multiple jurisdictions should check the New Zealand AD for any differences in requirements or timing, because the Directive does not describe the content of the New Zealand AD.

Clarity of disconnect means. The Directive permits use of a cable tie to collar the autopilot circuit breaker. Operators should ensure the cable tie practice meets applicable maintenance standards and does not introduce new hazards (e.g., difficulty in resetting in an emergency). The Directive instructs pulling and collaring the circuit breaker and specifically allows a cable tie as a method, but does not define a standard for collaring.

Record evidence needs. While the Directive implies the need for inspection, replacement and functional checks, it does not specify the form of record required to show compliance. Operators should anticipate a need to document the work clearly in maintenance records and to retain evidence to show that Requirements 2 and 3 were completed before returning the autopilot to service.

The Directive prescribes concrete steps that constitute compliance. The following is a stepwise checklist derived directly from the Directive’s Requirements and Notes. Implementers should follow the exact referenced service-bulletin instructions and drawings for the detailed technical procedures.

1. Confirm applicability.

   • Verify the aircraft identification: Model PAC 750XL and serial number 125, 126 or 127. The AD applies only to those serial numbers.

2. Immediate action before further flight (Requirement 1).

   • Pull and collar the autopilot circuit breaker to prevent re-engagement. The Directive allows the use of a cable tie to accomplish the collaring.
   • Install a placard in clear view of the pilot on or adjacent to the autopilot controller with the exact wording given in the Directive: "DO NOT USEPacific Aerospace Limited (PAC) 750XL Alert Service Bulletin (SB) PACASB/XL/001 dated 16 February 2007 refers."
   • Complete this step before further flight after 4 April 2007. Note that Requirement 1 is temporary and must remain in effect until Requirement 2 is accomplished (Note 1).

3. Inspect the pitch servo identification plate (Requirement 2).

   • Inspect the pitch servo identification plate and confirm the pitch servo part number (P/N) is 108-15-P1.
   • If the P/N is not 108-15-P1, replace the pitch servo with P/N 108-15-P1 in accordance with instruction 2.C. in PAC 750XL Mandatory SB PACSB/XL/025 dated 5 March 2007.
   • Note 2 indicates a replacement pitch servo P/N 108-15-P1 can be sourced from an authorised S-Tec dealer. Contact an authorised S-Tec dealer to obtain the replacement if required.

4. Reconnect and verify (Requirement 3).

   • After installing the correct pitch servo or confirming the existing part is P/N 108-15-P1, remove the cable tie on the autopilot circuit breaker and reset the circuit breaker.
   • Perform a functional check of the autopilot system. The Directive requires a functional check but does not set a detailed procedure in its text; follow the functional-check steps contained in PACSB/XL/025 or other applicable maintenance manuals and the organisation’s standard maintenance release procedures.
   • Upon successful functional verification, remove the “DO NOT USE” placard. Requirements 2 and 3 must be accomplished before returning the autopilot system to service.

5. Modify the autopilot system within the specified time window (Requirement 4).

   • Modify the autopilot system in accordance with paragraph 2.B. of SB PACSB/XL/025 and PAC Drawing 11-81639 Issue C.
   • Complete the modification within the next 150 hours time in service after the effective date of the Amendment (the Amendment is effective 2 April 2007, so operators must count 150 hours time-in-service from that date).
   • Ensure that the modification is performed by appropriately authorised maintenance personnel and that installation matches the drawing and SB requirements.

6. Documentation and certification.

   • Although the Directive text does not set out recordkeeping specifics, standard maintenance practice requires documenting the inspection, replacement, functional checks and the modification in the aircraft’s maintenance log and certifying release to service in accordance with applicable maintenance release requirements.
   • Retain records showing compliance with Requirement 1 (placard and circuit-breaker collaring), Requirement 2 (inspection and part replacement details including part number), Requirement 3 (functional check and placard removal) and Requirement 4 (modification per SB/drawing and associated sign-off).

7. Obtain and follow referenced documents.

   • Obtain PAC 750XL Mandatory SB PACSB/XL/025 dated 5 March 2007 and PAC Drawing 11-81639 Issue C, and follow the specific instructions referenced in the AD: instruction 2.C. for servo replacement and paragraph 2.B. for the required modification. Also consult PAC Alert SB PACASB/XL/001 dated 16 February 2007 as referenced on the placard wording and for context.
   • Confirm whether the CAA(NZ) AD DAC/750XL/12A contains any additional or divergent requirements if the aircraft is operated under or interacts with New Zealand regulatory control (Note 3).

8. Practical considerations and scheduling.

   • Plan for potential lead time to source the P/N 108-15-P1 servo from an authorised S-Tec dealer. Note 2 suggests such parts are available via authorised dealers, but the AD does not specify stock levels or delivery times.
   • Track time-in-service carefully for the 150-hour modification window and schedule the modification to avoid operating beyond the prescribed period without the mandated modification.

9. Maintenance standards and competence.

   • Ensure all work is conducted by appropriately licensed and authorised engineers or maintenance organisations in accordance with the maintenance organisation’s procedures and the referenced service bulletin instructions.
   • Perform functional checks to the standard required by the SB and by usual maintenance-release certification rules.

10. Cross-jurisdictional coordination.

• If the aircraft is registered in, or operated from, a jurisdiction that has acted on the same issue (for example, New Zealand’s CAA AD noted in Note 3), check both CASA and that authority’s requirements and ensure coordinated compliance. The AD text does not provide the content of the CAA(NZ) AD; consult the New Zealand AD as required.

Following these steps, and adhering to the exact referenced SB instructions and drawing, will implement the actions mandated in AD/750XL/9 Amendment 1. The Directive requires operators to perform the listed actions by the stated deadlines; operators should keep verifiable records to demonstrate compliance when requested by the regulator.