AD/PA-24/14 Amdt 2 - Exhaust System - Inspection

This Amendment centres on a small set of tightly defined technical and procedural concepts drawn from the AD framework and the aircraft manufacturer’s service materials. The main concepts in the text are: applicability, inspection scope and standard, conditions permitting discontinuation of repetitive inspections, compliance timing, and the instrument’s lineage.

• Applicability. The text sets out which models and serial-number ranges the Amendment covers: "Models PA-24, PA-24-250 and PA-24-260 except PA-24-260 with serial numbers 24-4783, 24-4804 and subsequent." It explicitly excludes PA-24-400 as part of aligning with USA AD 68-05-01, according to the "Background" paragraph.

• Inspection scope and standard. The inspection obligation is defined by component and by reference. Components required to be inspected are listed precisely: "engine exhaust muffler and shroud assembly (including the internal baffle tube and tail pipe), carburettor heat shroud and air duct, support braces, clamps and brackets, exhaust stacks and manifolds." The inspection must be carried out "in accordance with USA AD 68-05-01." The Amendment therefore imports the substantive inspection method and checks from that USA AD into the Australian directive.

• Discontinuation criteria. The Amendment sets out concrete hardware or modification conditions under which the repetitive inspection may be discontinued. For PA-24 aircraft, installation of hollow muffler P/N 24506 or P/N 26385 allows discontinuation. For PA-24-250 aircraft, the same hollow muffler numbers must be installed "in combination with muffler support Kit No. 756775 or Kit No. 757058." For PA-24-260 aircraft, installing "a barrier device in each muffler in accordance with Piper Service Letter No. 518" allows discontinuation. Those parts, part numbers and kit numbers are discrete technical triggers established by the instrument.

• Compliance timing. The Amendment ties the inspection obligation to maintenance release scheduling: "At each scheduled inspection for issue of a maintenance release following the date of effectivity of this Amendment." The "Background" notes that the previous compliance period had been each 100 hours, and that this Amendment changes the period to each maintenance-release inspection.

• Lineage and references. The Amendment explicitly references USA AD 68-05-01 and lists Piper Service Letters 324B, 324C, 412A, 481 and 518 as relevant. The "Background" provides a succinct lineage: original AD in 1963, Amendment 1 in 1969, and this Amendment which aligns with the USA AD and adjusts applicability and compliance timing.

Taken together, the instrument combines a prescriptive technical inspection checklist with a compliance timetable and a narrowly defined escape valve, the latter conditioned on installing authorised parts or kits or following a specific service letter procedure. The text therefore sets a simple rule: inspect specified exhaust-related components at every maintenance-release inspection unless one of the expressly listed hardware remedies has been fitted in the manner required.

The instrument affects operators and maintenance organisations responsible for the listed Piper PA-24 series aeroplanes within the scope stated under "Applicability." The text identifies models explicitly: "Models PA-24, PA-24-250 and PA-24-260," and excludes "PA-24-260 with serial numbers 24-4783, 24-4804 and subsequent." The "Background" further records that PA-24-400 is excluded as the Amendment specifies compliance with USA AD 68-05-01, which excludes the PA-24-400 and certain PA-24-260 examples. From the text, those who therefore carry the obligation are: the owners and operators of the applicable aircraft, and the maintenance personnel and organisations responsible for inspections and maintenance releases.

More concretely, the actors who face direct operational impact are those who perform scheduled inspections that lead to the issue of a maintenance release. The compliance requirement is stated: "At each scheduled inspection for issue of a maintenance release following the date of effectivity of this Amendment." The document therefore places an obligation on anyone maintaining the aircraft in a way that issues or relies upon a maintenance release certification. The duty is process-linked: it attaches to the scheduled maintenance release event rather than a fixed hours interval.

The instrument also imposes an economic effect on owners/operators because it creates an either-or pathway: continue recurring inspection at each maintenance release, or invest in specified parts/modifications that allow discontinuation of the recurring inspection. The parts and kits listed are named precisely by part numbers and kit numbers: hollow muffler P/N 24506 or P/N 26385 for PA-24; P/N 24506 or P/N 26385 plus muffler support Kit No. 756775 or Kit No. 757058 for PA-24-250; and a barrier device per Piper Service Letter No. 518 for PA-24-260. Operators deciding whether to install those parts will bear the procurement and installation costs. The instrument does not allocate cost recovery or subsidies; that financial obligation is implied for the affected operators.

The signature block names the enforcing administrative actor. The document is signed "Charles Lenarcic, Delegate of the Civil Aviation Safety Authority" which identifies the issuing authority and the delegate who enacted this Amendment. The instrument thus binds operators within the Australian regulatory environment and signals the authoritative issuer responsible for the directive.

Duties

• Conduct inspections. The core duty imposed by the Amendment is to "Inspect the engine exhaust muffler and shroud assembly (including the internal baffle tube and tail pipe), carburettor heat shroud and air duct, support braces, clamps and brackets, exhaust stacks and manifolds in accordance with USA AD 68-05-01." The duty is exacting in scope, listing the components and prescribing an external inspection standard by reference to USA AD 68-05-01. The inspection must be undertaken "At each scheduled inspection for issue of a maintenance release following the date of effectivity of this Amendment."

• Follow the referenced standards. The duty includes compliance with the procedures and checks set out in USA AD 68-05-01. The Amendment therefore incorporates external technical requirements into the domestic regulatory obligation.

Rights and options

• Discontinue repetitive inspections under specified conditions. Operators have a conditional right to stop the repetitive inspections when certain hardware or modifications are installed. The Amendment specifies three discontinuation routes, depending on model:

  • PA-24 aircraft: if hollow muffler P/N 24506 or P/N 26385 is installed, the repetitive inspection "may be discontinued."
  • PA-24-250 aircraft: if hollow muffler P/N 24506 or P/N 26385 is installed in combination with muffler support Kit No. 756775 or Kit No. 757058, the repetitive inspection "may be discontinued."
  • PA-24-260 aircraft: if a barrier device is installed in each muffler "in accordance with Piper Service Letter No. 518," the repetitive inspection "may be discontinued."

The instrument frames these as permissive options rather than mandatory modifications, so operators can choose to continue with periodic inspections rather than fitting the hardware.

• Reference to service literature. The Amendment lists "Piper Service Letters 324B, 324C, 412A, 481 and 518 are relevant," which gives operators a set of manufacturer guidance documents to consult when performing the inspections or modifications named. This functions as a rights-of-information element: the operator has the right to consult the specified service letters to satisfy the inspection or modification conditions.

Prescriptive detail and administrative linkage

• Timing tied to maintenance release. The duty is pragmatically linked to the maintenance-release process: inspections must be performed "at each scheduled inspection for issue of a maintenance release following the date of effectivity." That imposes an administrative rhythm on the duty, making it a recurring obligation in the regular maintenance cycle.

• Authority and effectivity. The Amendment becomes effective on 20 November 2008 and is issued by a CASA delegate. Those two data points establish the temporal and institutional boundaries of duties and rights.

What the instrument does not state

• Monetary penalties, enforcement mechanisms, or certification consequences are not detailed in the text. The Amendment identifies the inspection obligation and conditions for discontinuation, but it does not specify fines, sanctions, or administrative procedures for non-compliance in the body of the provided text. Similarly, it does not specify who certifies that discontinuation conditions have been correctly implemented; the operator and maintenance organisation will need to interpret the requirement in the context of maintenance-release procedures.

In sum, the instrument creates a clear inspection duty and a conditional right to cease inspections contingent on discrete parts or modifications, and ties the duty to the maintenance-release schedule. The operator’s choices are therefore between bearing recurring inspection effort or incurring one-off modification costs to stop the recurrence.

The instrument, as provided, does not specify penalties, fines, or detailed enforcement procedures within its text. The document sets out an obligation to inspect and provides an effective date, a delegate's signature, and directions as to the standard and timing of inspection, but it does not include a clause that prescribes sanctions for non-compliance in the text supplied.

Enforcement implications that can be read from the text

• Issuing authority. The Amendment is signed by "Charles Lenarcic, Delegate of the Civil Aviation Safety Authority." That signature identifies the issuing administrative authority and implies that compliance will be overseen through the Civil Aviation Safety Authority's regulatory framework. The instrument therefore sits within CASA’s enforcement domain, but the text itself contains no procedural or penalty provisions.

• Maintenance-release mechanism as compliance checkpoint. The instrument ties the inspection obligation to the scheduled inspection that issues a maintenance release: "At each scheduled inspection for issue of a maintenance release following the date of effectivity of this Amendment." By anchoring the inspection to maintenance-release events, the instrument embeds the requirement into the maintenance certification process. In practice, that linkage implies that the absence of an inspection at a scheduled maintenance-release checkpoint may be detectable through maintenance-release records. The Amendment does not specify how CASA will utilise those records to enforce compliance.

• No explicit penalty schedule. There is no stated fine, criminal penalty, administrative sanction or remedial power set out in the text provided. The absence of express penalties in the instrument means one must look to the broader regulatory regime for enforcement mechanisms. The text itself remains silent on the mechanisms CASA will deploy to ensure adherence, or on whether failure to comply will affect airworthiness certificates, registrations, or insurance.

• Delegated authority and amendment process. The Amendment records its lineage and changes to prior AD requirements, including the change in compliance interval and aligned references to USA AD 68-05-01 and specific Piper Service Letters. The fact that the instrument is an AD and is issued by a CASA delegate indicates it is part of the regulatory toolset that CASA uses to impose airworthiness obligations. The instrument thus carries the administrative weight of an AD, even though explicit penalties are not included here.

Practical consequences for operators

• Record-keeping risk. Because the inspection obligation is tied to maintenance releases, operators who cannot produce maintenance-release records demonstrating the required inspections may face regulatory scrutiny. The text itself does not state this explicitly, but the interaction between inspection timing and maintenance-release issuance creates an evidentiary pathway for enforcement actions under the broader regulatory framework.

• Modification vs inspection choice. Operators choosing to discontinue inspections by installing the parts or kits listed will need to document installation in a way that records compliance with the discontinuation criteria. The Amendment does not specify who validates installation or how it is to be recorded, so the responsibility to document compliance rests with the operator and the maintenance organisation.

Summary

The Amendment imposes a clear inspection duty, names the authority issuing it, and sets an effective date, but it does not set out penalties or enforcement procedures in the provided text. Enforcement activity, penalties and administrative remedies are therefore matters that would arise from the broader Civil Aviation regulatory framework rather than from discrete provisions in the instrument text included here.

The instrument explicitly cross-references external directives and manufacturer service literature, thereby creating direct legal and procedural connections to other instruments. Within the text the principal interactions are:

• Adoption of USA AD 68-05-01 as the inspection standard. The "Requirement" paragraph mandates inspections "in accordance with USA AD 68-05-01." That incorporation by reference means the substantive inspection procedures, checks and potentially remedial actions detailed in USA AD 68-05-01 become the operative standard for compliance under this Australian Amendment. The Amendment therefore operates in functional dependence on an overseas airworthiness directive.

• Reliance on Piper Service Letters. The Amendment lists "Piper Service Letters 324B, 324C, 412A, 481 and 518" as relevant. It also uses Service Letter No. 518 as the specific procedural authority for installing a barrier device to allow discontinuation of repetitive inspections on PA-24-260 aircraft. By naming these service letters, the instrument ties compliance to manufacturer-issued instructions and historical service literature.

• Relationship to the existing AD/PA-24/14. The instrument is labelled "AD/PA-24/14 Amdt 2" and the "Background" describes the original issue of the AD in 1963 and Amendment 1 in 1969. This Amendment therefore functions as a modification to an existing domestic AD. Its changes include specifying compliance with USA AD 68-05-01, narrowing applicability in line with that USA AD, and changing the compliance interval from "each 100 hours" to "each maintenance release inspection." The Amendment therefore updates the domestic AD to align with the referenced USA AD and modified maintenance cadence.

• Maintenance-release regulatory processes. The compliance timing "At each scheduled inspection for issue of a maintenance release" links the AD to the administrative process of issuing maintenance releases. Although the instrument does not detail the broader maintenance-release regulation, it embeds the AD's inspection duty into that procedural checkpoint.

Limits of interaction set out in the text

• No express integration clause. The instrument does not contain a clause stating how conflicts among USA AD 68-05-01, Piper Service Letters, and domestic regulations should be resolved. It simply requires inspections "in accordance with USA AD 68-05-01" and notes which service letters are relevant. Therefore, where the domestic regulatory framework differs in form from those referenced instruments, the Amendment does not specify an order of precedence within its text.

• No explicit procedural enforcement provisions. The instrument does not detail how CASA will monitor or enforce compliance, nor how maintenance organisations should record compliance beyond the maintenance-release tie. Those operational details fall outside the text and into the general civil aviation regulatory regime, but the Amendment’s direct interactions are confined to the three types of documents it references: the USA AD, specified Piper service letters, and the domestic AD it amends.

Practical consequences for operators and maintainers

• Technical compliance requires consulting external materials. Compliance with this Amendment requires access to USA AD 68-05-01 and the named Piper Service Letters. The instrument makes those external documents part of the operative standard for safe operation and maintenance.

• Compliance documentation will involve cross-referencing. Because the instrument imports standards from the USA AD and service letters, maintenance records will need to show that inspections were performed in accordance with those referenced documents if asked by an inspector or if an operator seeks to claim that the discontinuation criteria have been lawfully satisfied.

In short, the Amendment creates direct linkages to an overseas AD and to manufacturer service literature, updates a domestic AD, and ties inspection obligations to domestic maintenance-release procedures. The instrument does not itself reconcile conflicts or specify enforcement mechanisms; those matters are left to the broader regulatory framework and to operationalisation by maintenance organisations and CASA.

The text includes a concise amendment history and lineage for the AD relating to Piper PA-24 series aeroplanes. The salient chronological points recorded in the instrument are:

• Original AD issue, 1963. The "Background" states that "The original issue of this AD in 1963 specified compliance with Piper Service Letter No. 324B which covered models PA-24 and PA-24-250." That records the earliest identified version in the chain.

• Amendment 1, 1969. The "Background" continues that "Amendment 1 in 1969 specified compliance with Piper Service Letter No. 324C which also covered models PA-24-260 and PA-24-400." Amendment 1 therefore expanded the models captured by the AD and moved the maintenance reference to a later service letter.

• Present Amendment (Amdt 2), 2008. The document is styled "AD/PA-24/14 Amdt 2" and includes material indicating it is a later amendment updating the AD. The "Background" explains the present Amendment's scope and key changes: "This Amendment specifies compliance with USA AD 68-05-01 which excludes PA-24-400 and certain examples of PA-24-260; and allows discontinuation of repetitive inspections in some circumstances. The compliance period has been changed from each 100 hours to each maintenance release inspection." The instrument then records its effective date: "This Amendment becomes effective on 20 November 2008." The signature block includes the date 10 October 2008 with the signature "Charles Lenarcic, Delegate of the Civil Aviation Safety Authority."

• Cross-referenced service letters. The Amendment also lists a set of relevant Piper Service Letters across the AD lineage: "Piper Service Letters 324B, 324C, 412A, 481 and 518 are relevant." Those service letters trace the technical guidance that has been referenced through successive iterations of the AD.

Observable amendment mechanics

• Scope narrowing and alignment with USA AD. The most concrete mechanical amendment effected by Amdt 2 is alignment with USA AD 68-05-01, which in turn narrows applicability by excluding PA-24-400 and some PA-24-260 examples. The instrument explicitly records that alignment as a rationale.

• Change in compliance interval. Amdt 2 replaces an earlier 100-hour compliance interval with a maintenance-release-tied inspection rhythm. The "Background" sets this out as a change implemented in the present Amendment.

Administrative provenance and signature

• Delegate signatory and issuance timing. The instrument carries the name "Charles Lenarcic" and the title "Delegate of the Civil Aviation Safety Authority." It records the date 10 October 2008 alongside a graphical element and states the Amendment's effective date as 20 November 2008. Those data points show the Amendment's administrative origin within CASA and the lead time between signature and effectivity.

Summary

The Amendment history provided inside the document traces a straightforward lineage: an original 1963 AD referring to a Piper service letter, a 1969 amendment broadening model coverage and updating the service letter, and the present 2008 amendment that aligns with an overseas AD, narrows applicability by excluding certain models or serial ranges, and shifts the inspection interval from hours-based to maintenance-release-based. The instrument lists relevant service letters used across that lineage, establishing the technical literature that underpins each stage.

The instrument as provided contains no litigation history, references to court decisions, or records of legal challenges. The text is limited to administrative content: applicability, requirement, compliance timing, background, effective date and signatory. It records the provenance of prior amendments and references technical documents, but it does not include any mention of litigation, appeals, or judicial review arising from this AD or its earlier versions.

What the absence of litigation references in the text implies, as shown by the instrument

• No recorded cases cited. The document does not name any legal proceedings, court decisions or determinations relevant to the AD, past amendments, or the present Amendment. There are no citations to judicial interpretations of the AD or to disputes over its application.

• Administrative instrument focus. The document is an administrative directive aimed at specifying inspection obligations and conditions. The absence of litigation material is consistent with the usual administrative format of airworthiness directives, which primarily record technical requirements rather than legal controversies.

• Potential for external judgments outside the instrument. The text neither asserts that no litigation has occurred nor provides any assurance about legal status beyond the Amendment itself. It simply does not address litigation. Therefore, any litigation or judicial proceedings that might relate to this AD would fall outside the text of the instrument supplied.

Consequences for researchers and practitioners

• No judicial precedents or interpretations to cite from the instrument. Practitioners relying solely on this text will not find case law, appellate findings, or judicial clarifications within the document. Any legal arguments that depend on judicial interpretation of AD/PA-24/14 or its amendments would require sourcing external case material, which is not provided here.

• Operational clarity remains administrative. Because the instrument focuses on prescriptive technical obligations and does not invoke litigation or dispute resolution context, operational compliance analysis should proceed on the basis of the written requirements and the broader administrative regime rather than on reported judicial decisions derived from the instrument.

In sum, the supplied Amendment contains no litigation history, and the text does not indicate that any litigation has been considered or adjudicated in relation to the AD or its amendments. Any analysis that required the presence of judicial material would need external sources beyond this instrument.

The instrument contains several discrete technical and procedural features that are likely to produce misunderstandings or misapplication if not closely read. These are practical "gotchas" grounded in the text.

1. Applicability exclusions are serial-number specific. The applicability line reads: "Models PA-24, PA-24-250 and PA-24-260 except PA-24-260 with serial numbers 24-4783, 24-4804 and subsequent." Operators may misread this as covering all PA-24-260 aircraft or as excluding only the two serials named; the text excludes the named serial numbers "and subsequent," which means aircraft at or beyond serial numbers 24-4783 and 24-4804 are excluded according to the wording. The instrument does not explain the reason for the serial-number cut-off; it simply reflects the scope of USA AD 68-05-01 as recorded in "Background." Careful interpretation of serial ranges will be necessary to avoid mistakenly applying the inspection to excluded airframes.

2. Discontinuation triggers are model-specific and conditional. The instrument provides three different discontinuation criteria that vary with model. For PA-24-250, the hollow muffler alone is insufficient; it must be installed "in combination with muffler support Kit No. 756775 or Kit No. 757058." For PA-24-260, the discontinuation depends on installation "in accordance with Piper Service Letter No. 518" of a barrier device. The phrase "in accordance with" signals that the installation must follow the service letter instructions; operators who merely install a barrier device without following the service letter may not meet the condition.

3. Shift from a fixed hours interval to maintenance-release timing. The "Background" notes the compliance period has changed "from each 100 hours to each maintenance release inspection." The operative "Compliance" line states inspections are required "At each scheduled inspection for issue of a maintenance release following the date of effectivity of this Amendment." Operators accustomed to a 100-hour clock may mis-time or miss inspections if their maintenance-release schedule does not align with prior assumptions about 100-hour intervals.

4. Reliance on external documents for procedure. The inspection must be performed "in accordance with USA AD 68-05-01," and several Piper Service Letters are listed as relevant. The Amendment does not reproduce the procedures from those documents. Operators must obtain and follow USA AD 68-05-01 and the named service letters. Failure to consult and apply those external materials could lead to an inspection that does not satisfy the AD’s requirements.

5. No enforcement or penalty language provided. The instrument lacks explicit penalty, rectification or enforcement procedures. That absence can create uncertainty about the consequences for non-compliance. Operators may assume enforcement is lenient because no penalties are listed, but the AD is issued by CASA and the maintenance-release linkage provides an administrative touchpoint for compliance checks. The instrument does not explain how CASA will act in the event of non-compliance.

6. Discontinuation is permissive, not mandatory. The instrument uses the phrase "may be discontinued" when listing circumstances that allow stopping repetitive inspections. That permissive wording means an operator may choose either to carry out the repeated inspections or to implement the listed modifications to discontinue them. The right to discontinue is conditional on correct installation and, in some cases, following specific service letter procedures. Operators must document compliance precisely if they seek to rely on discontinuation.

7. Multiple, potentially overlapping service letters. The instrument lists five service letters as relevant: 324B, 324C, 412A, 481 and 518. Some of these service letters pre-date the present Amendment and some are model-specific. Operators must determine which service letter instructions are applicable to their particular airframe and to the specific installation or inspection step they undertake. Failing to identify the correct service letter could result in non-conforming action.

8. Effective date vs signature date. The document is signed on 10 October 2008 and declares "This Amendment becomes effective on 20 November 2008." Compliance obligations begin after the effective date for maintenance-release inspections. Operators must ensure they apply the new compliance timing from 20 November 2008 onwards and not earlier or later.

These "gotchas" are textual and procedural. They arise from the instrument’s serial-number-based applicability, model-specific discontinuation conditions, reliance on external technical documents, and the change in inspection cadence. Operators and maintainers should plan procurement, installation, documentation and inspection timing with these features expressly in mind.

This section sets out a practical, text-grounded checklist for meeting the obligations imposed by the Amendment, strictly using the instrument’s language and the documents it references.

1. Determine applicability precisely. Consult the "Applicability" line in the Amendment: "Models PA-24, PA-24-250 and PA-24-260 except PA-24-260 with serial numbers 24-4783, 24-4804 and subsequent." Confirm the aircraft model and serial number against those exact strings. If the aircraft is a PA-24-400, note that the "Background" states this Amendment mirrors USA AD 68-05-01 which excludes PA-24-400; the instrument therefore does not apply to PA-24-400 airframes under the text provided.

2. Adopt the prescribed inspection standard. The "Requirement" directs inspections "in accordance with USA AD 68-05-01." Obtain a copy of USA AD 68-05-01 and follow the inspection procedures, checklists, and acceptance criteria set out there when inspecting the components listed in the Amendment: the engine exhaust muffler and shroud assembly, including internal baffle tube and tail pipe; carburettor heat shroud and air duct; support braces, clamps and brackets; exhaust stacks and manifolds.

3. Inspect the explicitly listed components. The Amendment specifies the scope of work. At the maintenance-release inspection, ensure that the following items are inspected as part of the maintenance-release process:

   • Engine exhaust muffler and shroud assembly, including the internal baffle tube and tail pipe.
   • Carburettor heat shroud and air duct.
   • Support braces, clamps and brackets.
   • Exhaust stacks and manifolds.

Use the procedures and acceptance criteria in USA AD 68-05-01.

4. Schedule inspections to align with maintenance releases. The "Compliance" line states inspections are required "At each scheduled inspection for issue of a maintenance release following the date of effectivity of this Amendment." Incorporate this requirement into the aircraft’s scheduled maintenance plan so that every scheduled inspection that results in issuance of a maintenance release includes the exhaust-system inspection.

5. Consider the discontinuation options and document installation work. If the operator prefers to discontinue repetitive inspections, follow the model-specific criteria precisely and document the installation:

   • For PA-24 aircraft: install hollow muffler P/N 24506 or P/N 26385. Record the part number, installation date, installer, and any referenced maintenance release.

   • For PA-24-250 aircraft: install hollow muffler P/N 24506 or P/N 26385 in combination with muffler support Kit No. 756775 or Kit No. 757058. Record both part numbers and kit numbers, installation compliance details and maintenance-release sign-off.

   • For PA-24-260 aircraft: install a barrier device in each muffler "in accordance with Piper Service Letter No. 518." Acquire Service Letter No. 518 and follow its instructions exactly. Document that the installation adhered to the service letter, and ensure maintenance records reflect the method and sign-off.

6. Maintain contemporaneous and accessible records. Because the Amendment ties inspections to maintenance-release events, ensure that maintenance-release documentation explicitly records the exhaust-system inspection or the installation of discontinuation hardware. Include references to USA AD 68-05-01 and to any Piper Service Letter used. Good practice consistent with the instrument requires noting part numbers, kit numbers, service-letter references and dates.

7. Consult the listed Piper Service Letters where relevant. The Amendment lists Service Letters 324B, 324C, 412A, 481 and 518 as relevant. Obtain and review the ones that are applicable to the airframe or the specific inspection/modification being performed. Use the service letters for technical guidance and to ensure installations meet the conditions set out by the Amendment, especially where discontinuation depends on compliance with a specific service letter (Service Letter No. 518 for the PA-24-260 barrier device).

8. Note the effective date for planning and retrofitting. The Amendment becomes effective on 20 November 2008. For maintenance planning and compliance purposes, ensure that scheduled inspections after that date include the required exhaust-system inspection unless the discontinuation conditions have been met and documented.

9. Coordinate with maintenance organisation authorisations. While the Amendment does not specify administrative enforcement, it ties compliance to maintenance-release issuance. Ensure that the maintenance organisation undertaking or certifying the inspection is authorised under whatever domestic maintenance regulatory framework applies, and that it documents inspections and installations in the maintenance-release paperwork.

10. Retain audit evidence for audit or regulatory inspection. Although the instrument does not specify penalties, retain evidence that inspections were performed in accordance with USA AD 68-05-01 or that discontinuation modifications were installed in accordance with the named service letters and kit instructions. Maintain records of part numbers, kit numbers, service letters, installation dates, installer identity and maintenance-release references.

By following those steps, an operator will adhere to the Amendment’s substantive and procedural requirements as stated in the instrument: perform the specified inspections at each scheduled maintenance-release inspection unless one of the enumerated discontinuation conditions applies, in which case document installation precisely and retain supporting records.