AD/B727/99 Amdt 4 - No. 3 Cargo Door Frame

The instrument uses several self-contained concepts and cross-references that determine legal and operational effect. Below are the principal concepts as presented in the source, with their operational implications.

Applicability by reference. The instrument does not list individual airframes or serial numbers in-line; it identifies the affected fleet by reference to "Model 727-200 series aircraft, equipped with a No. 3 cargo door; as identified in Boeing Alert Service Bulletin 727-53A0169 Revision 2, or later FAA approved revision" (Applicability). The practical implication is that inclusion in the Boeing alert service bulletin (or later FAA-approved revision) is the criterion that brings a specific aeroplane within the AD's reach. The instrument therefore imports Boeing's SB as the descriptive list and FAA approval as the update mechanism.

Imported technical standard. The requirement states operators must take "Action in accordance with the technical requirements of FAA AD 2006-13-01 Amdt 39-14653" (Requirement). The CASA AD does not itself set out detailed inspection tasks; it makes another regulator's AD the operational specification. The FAA AD is the technical standard being mandated for Australian-registered aeroplanes in this class.

Inspection, repair and modification lifecycle. The Background summarises a sequence of responses to detected cracking: (1) initial inspections of a specified area; (2) expanded inspection area and extra inspections for repaired frames (Amendment 3); (3) a structural modification designed to produce "crack free frames", which when installed terminated the repetitive inspection requirement (Amendment 3 summary); and (4) Amendment 4 shortens initial compliance times, adds an optional inspection method, and introduces inspections of an additional area in response to further cracking reports (Background). Thus the AD operates along the inspection/repair/modify continuum: inspections detect cracking; repaired frames require closer follow-up; and a full modification can substitute for repetitive inspections.

Optional methods vs mandatory modifications. Amendment 4 "adds an optional method of inspection for both the initial and repetitive inspections" (Background). Separately, the instrument clarifies that an earlier "optional structural modification is now required by other rulemaking (90-06-09, AD/B727/118 Amdt 1)" (Background). The interplay means operators may have choice in inspection technique but not necessarily in whether to perform certain structural modifications, depending on the separate AD referenced.

Safety trigger. The instrument is motivated by reported "fatigue cracks occurring in the forward frame and fuselage skin of the No. 3 cargo door cut-out" and the risk that "Undetected cracking could eventually lead to failure of the frame and skin, and consequent rapid decompression" (Background). That safety risk is the explicated problem the inspections and modifications aim to reduce.

Temporal effect. The document includes a revised effective date: "This Amendment becomes effective on 3 August 2006" and the Compliance paragraph refers to the requirement document "with a revised effective date of 3 August 2006." The AD therefore imposes both technical actions and a binding timeline for when those actions must be in place.

Delegated signature. The AD is executed by a CASA delegate, David Villiers, showing the decision authority that issues the directive. The text does not itself set out enforcement mechanics or penalties, but it establishes mandatory compliance with the referenced FAA AD for the named fleet.

The universe of affected persons and organisations is narrowly defined by the instrument. The document names the affected aeroplane type and the documents that identify specific airframes, and from that we can derive the primary affected parties and secondary stakeholders.

Primary affected parties

• Operators and owners of Boeing Model 727-200 series aircraft that are "equipped with a No. 3 cargo door" and are "identified in Boeing Alert Service Bulletin 727-53A0169 Revision 2, or later FAA approved revision" (Applicability). If an aeroplane is included in that Boeing SB revision (or later FAA-approved revision), its operator must comply with the FAA AD actions mandated by this CASA AD.
• Maintenance organisations, licensed aircraft maintenance engineers and MRO shops that perform the inspections, repairs and structural modifications prescribed in the FAA AD and the Boeing service bulletin. The AD's technical content is incorporated by reference to FAA AD 2006-13-01; therefore the entities that carry out those technical tasks are directly affected.
• Lessors, financiers and certificate holders with operational control of affected aeroplanes, because responsibility for continuing airworthiness and compliance with ADs lies with the operator or maintainer named in registration and maintenance records. The source does not allocate cost-sharing; it prescribes mandatory technical action for aircraft that satisfy the applicability criteria.

Secondary affected parties

• Scheduling and flight operations personnel, because reduced initial compliance times and added inspections will affect aircraft availability and may require flights to be removed from service for maintenance windows. The AD reduces the time operators have to perform initial inspections relative to previous amendments.
• Supply chains for spares and modification kits. Amendment 3 introduced an "improved modification for crack free frames" and Amendment 4 refers to that modification and to inspections of additional areas. If operators choose the modification, they will need the means to procure parts and design approval where required by the FAA AD.
• CASA as regulator, which must manage the effective date and communicate the AD to the Australian aviation community; the AD is signed by a CASA delegate (David Villiers) and therefore imposes obligations in the Australian regulatory control environment.

What is not affected, per the text

• Model types other than 727-200 series are not in scope unless they are identified in the referenced Boeing Alert Service Bulletin, which the Applicability confines to Model 727-200 series. The AD is not a generic obligation across all Boeing 727 types as stated.
• Aeroplanes not listed in the Boeing Alert Service Bulletin Revision 2 (or later FAA-approved revision) are not, according to this instrument's wording, captured by the AD until and unless a later FAA-approved revision includes them.

Who pays and who decides

• The source places the obligation on operators of affected aeroplanes to carry out actions required by FAA AD 2006-13-01. The document does not allocate financial support or compensation; therefore the practical expectation is that operators bear the direct costs of inspections, repairs and modifications.
• Decision authority for the technical standard is effectively shared: CASA issues the AD and makes compliance mandatory in Australia, while the FAA AD supplies the detailed technical prescription that operators must follow. Boeing's service bulletin identifies affected airframes and the FAA approves revisions to that bulletin for applicability.

The instrument establishes a compact set of duties and some limited choices for operators. The text itself is short; the key operational duties and the limited rights that remain are summarised below, all grounded in the document's wording.

Primary duties (explicit in the instrument)

• Follow the FAA AD: The core duty is to "Action in accordance with the technical requirements of FAA AD 2006-13-01 Amdt 39-14653" (Requirement). The CASA AD does not reproduce the FAA AD's technical content; it imports that AD as the operative specification. Operators must therefore obtain FAA AD 2006-13-01 and perform the inspections, repairs and modification steps set out therein.
• Adhere to Applicability: Operators must identify whether an aeroplane falls within scope by reference to Boeing Alert Service Bulletin 727-53A0169 Revision 2, or later FAA-approved revision (Applicability). If an aeroplane is identified in that bulletin, the owner/operator has the duty to comply with the FAA AD actions as mandated by this CASA AD.
• Meet the specified timetable: The Compliance paragraph and the effective date impose timing obligations. The instrument states that it "becomes effective on 3 August 2006" and that compliance is "As specified in the Requirement document, with a revised effective date of 3 August 2006." Operators must therefore perform actions within the times prescribed in the FAA AD as modified by this effective date.

Secondary duties (derived from Background descriptions)

• Perform additional inspections for repaired frames, if those repaired frames are within the scope described in Amendment 3, which the Background summaries as having "introduced additional inspections of repaired frames" (Background). The imported FAA AD will contain the precise intervals; the CASA AD signals that repaired frames have extra inspection duties.
• Implement a structural modification if required by separate rulemaking. The Background clarifies that the previously optional structural modification "is now required by other rulemaking (90-06-09, AD/B727/118 Amdt 1)." Where that other AD applies, operators must implement the modification as required by it.

Rights and limited choices

• Optional inspection method: Amendment 4 "adds an optional method of inspection for both the initial and repetitive inspections" (Background). That language preserves a choice of technique in executing the inspection tasks, subject to the conditions and approvals set out in the FAA AD being followed. The presence of an "optional method" implies operators can elect between methods authorised by the FAA AD.
• Use of later FAA-approved revisions: The Applicability permits inclusion of aircraft identified in "Revision 2, or later FAA approved revision" of the Boeing Service Bulletin. That gives operators the right to rely on subsequent FAA-approved revisions to determine applicability, and allows the compliance scope to move forward if the FAA approves further revisions.

What the AD does not state (explicit absences)

• The CASA AD text does not set out the specific inspection procedures, intervals, repair definitions or modification instructions; those technical particulars are left to the FAA AD and the Boeing service bulletin it references.
• The document does not state procedural rights such as an administrative appeal mechanism or the steps for applying for an alternative method of compliance. The source simply imports the FAA AD.

Practical implications for duty-holders

• Operators must obtain the FAA AD and the Boeing Alert Service Bulletin revision identified to understand precise tasks, intervals and acceptance criteria. The CASA AD makes these documents mandatory insofar as they apply to aircraft listed in the Boeing bulletin.
• The interplay between optional inspection methods and mandatory modifications requires operators to map which obligations are imposed by this AD and which are imposed by other ADs (particularly AD/B727/118 Amdt 1), so they do not mistakenly treat required modifications as optional.

The instrument itself does not set out explicit penalties or enforcement procedures. The text contains mandatory language and an effective date, but it does not prescribe fines, suspensions or specific enforcement steps in the document provided. The key points from the source are:

No explicit sanctions in the text. The AD specifies the Requirement, Applicability, Compliance and Effective Date but does not include any penalty provisions, enforcement mechanisms, or administrative remedies. The document’s Background describes safety risk and the technical sequence of inspections and modifications, but it contains no enforcement clause nor references to sanctions for non-compliance.

Mandatory character. Despite the absence of explicit penalties in the short text, the Requirement uses mandatory wording: operators are to "Action in accordance with the technical requirements of FAA AD 2006-13-01 Amdt 39-14653." The Compliance paragraph reiterates that actions are "As specified in the Requirement document" with a defined effective date. That language imposes a binding obligation on operators of affected aeroplanes as of the effective date.

Delegated authority. The AD is signed by a CASA delegate, David Villiers. That signature indicates the directive is issued under CASA’s delegated powers and is intended to be enforceable as a regulatory instrument in the Australian aviation safety framework. However, the instrument itself does not elaborate the enforcement path or prescribe steps CASA will take to verify compliance or to sanction non-compliance.

Practical enforcement implications (source-grounded inference)

• The instrument imposes duties by mandating compliance with another regulator’s AD. Because the AD establishes mandatory technical tasks and a timetable, operators who do not perform those tasks will be outside the compliance standard the instrument creates. The source does not detail what CASA will do in response to non-compliance; therefore the reader must treat the AD as setting a mandatory standard while recognising the document contains no enforcement schedule, penalty rates, or procedural steps.

Due process and remedies. The source contains no statement about administrative review, avenues to seek alternative methods of compliance, or how to record deviations. The AD also does not state whether previously approved alternative methods of compliance remain valid, or whether operators must obtain new approvals for optional inspection methods.

What to watch for

• Because the AD imports the FAA AD as the technical standard, practitioners should consult FAA AD 2006-13-01 for any guidance the FAA provides about methods of compliance, approved alternative procedures, or the FAA’s enforcement expectations. The CASA AD itself does not reference those procedural topics.

This CASA AD interacts primarily by reference to other regulatory and technical instruments rather than by creating standalone, self-contained technical detail. The document’s own cross-references define its practical dependencies and the route by which compliance is established.

Direct cross-references contained in the instrument

• FAA AD 2006-13-01 Amdt 39-14653: The Requirement makes this the operative technical prescription for the actions to be taken. The CASA AD therefore imports another jurisdiction’s airworthiness directive as the substantive compliance standard for affected Australian-registered aeroplanes.
• Boeing Alert Service Bulletin 727-53A0169 Revision 2, or later FAA approved revision: The Applicability defines the affected aeroplanes by reference to this Boeing service bulletin. That means the AD’s scope is determined by Boeing’s technical identification of airframes and any later FAA-approved updates to that bulletin.
• AD/B727/118 Amdt 1 (90-06-09): The Background states that a previously optional structural modification is "now required by other rulemaking (90-06-09, AD/B727/118 Amdt 1)." That cross-reference indicates the CASA AD is not the sole source of obligation for the structural modification aspect; other CASA ADs interact and can convert optional modifications into mandatory ones.

Mechanism of legal interaction

• Incorporation by reference: The AD uses incorporation by reference as its prime method of interaction. Rather than repeating technical standards, it requires that operators follow FAA AD 2006-13-01 and determines which aeroplanes are affected by referencing Boeing’s service bulletin. That approach makes the CASA AD a pointer to, and enforcer of, technical requirements developed elsewhere.
• Amendment layering: The Background recounts a sequence of amendments (including Amendment 3 and Amendment 4) that changed inspection areas, inspection frequency, and modification options. The instrument therefore sits in a layered set of regulatory instruments in which each AD or amendment modifies prior obligations and interacts with other ADs (such as AD/B727/118 Amdt 1).

Practical consequences for compliance and legal interpretation

• Changes in referenced documents will change the AD’s practical operation. Because the Applicability allows "Revision 2, or later FAA approved revision" of Boeing’s bulletin to define affected aircraft, an FAA-approved later revision can expand or contract the population of aircraft captured by the AD without CASA issuing a new AD. Practitioners must therefore monitor FAA approvals of later service bulletin revisions.
• Where an obligation is moved from "optional" to "required" under a separate AD (AD/B727/118 Amdt 1), operators must reconcile the requirements of multiple ADs to determine current mandatory tasks. The CASA AD explicitly notes that a previously optional modification is now required by other rulemaking, signalling the need to check that other AD for mandatory timing and conditions.

What the instrument does not do

• It does not amend or repeal other ADs in text. The instrument references other ADs and service bulletins, but it does not contain textual provisions that expressly amend or supersede other CASA ADs. Any change in obligation is communicated by reference or by subsequent ADs elsewhere in CASA’s registry.
• It does not set out conflict-resolution rules for inconsistent technical requirements between the FAA AD and Australian ADs. The document assumes alignment by mandating the FAA AD’s technical requirements; where divergence arises, the practitioner must look to CASA’s overall regulatory regime for resolution, since this AD itself does not prescribe a conflict-handling rule.

The text supplied is Amendment 4 to AD/B727/99. The instrument summarizes previous changes and explains the reasons for the current amendment. The amendment history as recited in the source is as follows.

Original AD and prior amendments (as summarised)

• The Background references earlier action but does not provide the full text of prior amendments. It states that "Amendment 3 increased the area to be inspected, introduced additional inspections of repaired frames, and provided an improved modification for crack free frames, which terminated the repetitive inspection requirement." That indicates Amendment 3 enlarged the inspection footprint, imposed extra inspections for repaired frames, and made available a modification which, when installed, ended the need for continued repetitive inspections on a particular aeroplane.
• The Background also indicates the structural modification mentioned in earlier amendments had been optional, but subsequent rulemaking changed that status.

Amendment 4 (the current instrument)

• Rationale: Amendment 4 was "issued in response to a new FAA AD, which was prompted by additional reports of cracking in the forward frame of the No. 3 cargo door cut-out" (Background). The textual trigger is additional cracking reports that led the FAA to issue AD 2006-13-01, which CASA then adopted by reference.
• Changes introduced: Amendment 4 "reduces the compliance time for initial inspections, adds an optional method of inspection for both the initial and repetitive inspections, and introduces inspections of an additional area" (Background). In short, Amendment 4 tightened timelines, expanded inspection scope, and offered an optional inspection technique.
• Effect on previously optional modification: Amendment 4 clarifies that the "previously optional structural modification is now required by other rulemaking (90-06-09, AD/B727/118 Amdt 1)" (Background). The instrument therefore records that what was once optional has been made mandatory by a separate AD.

Dates and signatures

• Amendment 4 is dated 22 June 2006 (signature by David Villiers, Delegate of the Civil Aviation Safety Authority).
• The instrument contains an effective date: "This Amendment becomes effective on 3 August 2006" and the Compliance paragraph notes compliance "with a revised effective date of 3 August 2006."

What the amendment history implies operationally

• The instrument is part of a sequence of regulatory responses to detected fatigue cracking in the No. 3 cargo door cut-out. The cumulative response has included: enlarging inspection areas, adding inspections for repaired frames, developing and offering a modification to eliminate cracks, and tightening inspection timing in response to further cracking reports. Each amendment has adjusted the balance between repeated inspection burden and the adoption of a modification intended to remove the need for repetitive inspection.

Limitations of the supplied history

• The source summarises the prior amendments but does not provide the earlier AD texts, their full dates, or the detailed technical modifications those amendments required. It mentions AD/B727/118 Amdt 1 and 90-06-09 as other rulemaking that changes the legal status of the structural modification but does not reproduce their provisions. For precise chronology and wording of earlier ADs, one must consult the original AD/B727/99, Amendment 3, AD/B727/118 Amdt 1, and FAA AD 2006-13-01, none of which are reproduced in full in the supplied text.

The supplied instrument contains no reference to litigation, court decisions, appeals or judicial review arising from AD/B727/99 or its amendments. The entire AD text, as provided, is limited to regulatory content, applicability, technical import by reference, and an administrative signature; it contains no mention of any legal proceedings.

What the text says

• There are no case citations, no references to appeals or challenges, nor any recital of prior litigation history. The document records factual background about fatigue cracking reports and prior amendments but does not discuss disputes or judicial outcomes.

Practical note for practitioners (source-grounded)

• Because the instrument does not mention litigation, the document itself cannot be relied on to signal whether any party has challenged these measures in court or sought relief from CASA. The absence of litigation reference in the AD text does not prove absence of any challenge elsewhere; it merely records that this AD does not contain, reference or narrate litigation.

Consequences for legal work

• Where litigation history is material to risk assessment or to arguments about regulatory intent, enforceability or reasonableness, practitioners will need to consult external sources such as court records, administrative determinations or CASA’s public record beyond the AD itself. The AD supplied here does not provide that material.

Limitations

• The AD provides no procedural or remedial language (for example, no explicit administrative appeal steps or alternative method of compliance route in the text provided). If legal challenge or negotiation is contemplated, the AD is silent about the procedural forum and does not itself contain a dispute-resolution mechanism.

This instrument contains a number of specific textual features that create risks for operational or legal misinterpretation. Below are the principal pitfalls to watch for, each grounded directly in the AD text.

Scope defined by external documents

• Trap: Treating the AD as a standalone list of affected aeroplanes. The Applicability does not enumerate serial numbers in the AD; it points to "Boeing Alert Service Bulletin 727-53A0169 Revision 2, or later FAA approved revision." If an operator fails to consult the correct revision of the Boeing bulletin or to confirm whether a later FAA-approved revision changes the scope, it may mistakenly assume an aircraft is out of scope when it is in scope, or vice versa.

Imported technical content

• Trap: Assuming CASA has itself set technical details. The AD says to "Action in accordance with the technical requirements of FAA AD 2006-13-01 Amdt 39-14653." The CASA AD therefore delegates the technical detail to the FAA AD. Operators who do not obtain or read FAA AD 2006-13-01 may misunderstand required procedures, intervals or approved techniques.

Revised compliance time

• Trap: Missing the shortened initial inspection window. The Background states Amendment 4 "reduces the compliance time for initial inspections." The Compliance paragraph sets an effective date and instructs compliance "As specified in the Requirement document, with a revised effective date of 3 August 2006." Operators could rely on earlier inspection timelines if they do not track this amendment and the revised effective date.

Optional inspection method vs mandatory modification

• Trap: Confusing optional inspection technique with optional substantive obligation. Amendment 4 "adds an optional method of inspection for both the initial and repetitive inspections" but the Background also clarifies that the "previously optional structural modification is now required by other rulemaking (90-06-09, AD/B727/118 Amdt 1)." An operator might think optional inspection choice implies optional structural modification, which is incorrect where another AD makes that modification mandatory.

Repaired frames and inspection frequency

• Trap: Neglecting additional inspections for repaired frames. Amendment 3 "introduced additional inspections of repaired frames" and that change persists in the amendment history. Operators who perform repairs but do not implement the extra inspection regimen described in the FAA AD may fail to meet the AD’s obligations.

Timing and effective date misinterpretation

• Trap: Confusing the issuance date with the effective date. The AD is dated 22 June 2006 but "becomes effective on 3 August 2006." Treat 3 August 2006 as the compliance milestone. Failure to recognise the effective date could lead to either premature action or missed deadlines.

Assuming the AD contains enforcement or penalty detail

• Trap: Expecting penalty schedules or enforcement procedures in the AD text. The supplied instrument contains no enforcement or penalty provisions. Operating decisions should not be made on the assumption that the AD furnishes those details.

Reliance on prior termination of inspection

• Trap: Assuming that because Amendment 3 provided a modification that terminated repetitive inspections, your aeroplane is no longer subject to inspections. The Background indicates that the modification could terminate repetitive inspections, but Amendment 4 reintroduced inspection expansions, shortened initial inspection times, and other changes. Only where the modification has been installed and is now mandatory under AD/B727/118 Amdt 1 will the repetitive inspection termination necessarily apply. Cross-checking across ADs is required.

Recordkeeping and proof of compliance

• Trap: Underestimating the need to document which revision of the Boeing service bulletin and which FAA AD were used to determine applicability and compliance. The instrument’s reliance on external documents makes provenance of material decisions important; operators should maintain records showing which revision was consulted and how compliance was achieved.

The AD is concise, but it mandates a clear path to compliance by reference. The steps below are the source-grounded actions operators and maintainers should follow to meet the AD’s requirements.

1. Determine applicability using the Boeing service bulletin named in the AD.

• Obtain Boeing Alert Service Bulletin 727-53A0169 Revision 2 and check whether the specific airframe appears in that revision. The Applicability covers "Model 727-200 series aircraft, equipped with a No. 3 cargo door; as identified in Boeing Alert Service Bulletin 727-53A0169 Revision 2, or later FAA approved revision."
• If a later FAA-approved revision to that Boeing SB exists, obtain that revision and verify whether it alters applicability under the AD. The instrument explicitly allows "or later FAA approved revision" to determine the population of affected aircraft.

2. Obtain and follow FAA AD 2006-13-01 Amdt 39-14653.

• The Requirement states to "Action in accordance with the technical requirements of FAA AD 2006-13-01 Amdt 39-14653." Compliance requires implementing the inspection, repair and modification steps, intervals and acceptance criteria specified in that FAA AD.
• Pay attention to the FAA AD’s guidance on initial inspection intervals, repetitive inspections, repaired-frame inspection regimes, and any procedures for modifications or repairs that terminate repetitive inspections. The CASA AD does not reproduce those technical specifics but makes them mandatory.

3. Observe the AD’s timing and effective date.

• The AD is effective on 3 August 2006 and states compliance is "As specified in the Requirement document, with a revised effective date of 3 August 2006." Adopt the timings in FAA AD 2006-13-01 as modified by that effective date; if the FAA AD contains compliance windows relative to discovery or flight cycles, apply them within the constraint of the revised effective date.

4. Select inspection method where optional methods are authorised.

• Amendment 4 "adds an optional method of inspection for both the initial and repetitive inspections." Where FAA AD 2006-13-01 authorises an optional inspection method, choose the method that is acceptable under the FAA AD, ensuring any tooling, nondestructive inspection techniques or qualification requirements in the FAA AD are met.

5. Implement additional inspections for repaired frames.

• If a No. 3 cargo door frame has been repaired, apply the "additional inspections of repaired frames" referred to in Amendment 3 as required by the FAA AD and reflected in this AD’s history. The FAA AD will specify intervals and scope for such inspections.

6. Assess and implement required structural modifications.

• The Background notes that an "improved modification for crack free frames" was provided in Amendment 3 and that the structural modification that was previously optional "is now required by other rulemaking (90-06-09, AD/B727/118 Amdt 1)." Check AD/B727/118 Amdt 1 to determine any mandatory modification tasks and their timelines, and ensure modifications are fitted and documented where required.

7. Prepare logistics and schedule to avoid operational disruption.

• Because Amendment 4 "reduces the compliance time for initial inspections," planning is required to secure maintenance slots, qualified technicians and any required parts or kits. The AD itself does not provide resource or procurement guidance; operators must coordinate with maintenance providers and suppliers to meet the compressed timelines.

8. Keep contemporaneous records showing compliance with the referenced documents.

• Because the AD defines applicability and technical tasks by reference to external FAA and Boeing documents, maintain records that show which revision of Boeing SB was consulted, which edition of the FAA AD was followed, dates the inspections were performed, findings, repairs carried out, and modifications installed. The AD does not itself spell out recordkeeping processes, but records will be necessary to show compliance.

9. Where uncertainty exists, consult CASA guidance and the originating FAA AD.

• The CASA AD imports the FAA AD; for questions about interpretation, acceptability of an alternative method of compliance, or technical clarifications, consult the FAA AD text for guidance on approved alternatives, and engage CASA if domestic regulatory waivers or approvals are needed. The AD does not specify an alternative method process in the text provided.

10. Monitor for later revisions and related ADs.

• The Applicability contemplates "later FAA approved revision" of the Boeing SB. Additionally, the Background references other rulemaking (AD/B727/118 Amdt 1) that changed the status of a structural modification. Operators should monitor CASA and FAA AD bulletins for further amendments that affect inspection intervals, applicability or modification requirements.

In short, compliance under this instrument is achieved by (1) confirming a specific aeroplane is within the scope set by Boeing Alert Service Bulletin 727-53A0169 Revision 2 or a later FAA-approved revision, (2) obtaining and following the technical requirements in FAA AD 2006-13-01 Amdt 39-14653, and (3) implementing any structural modification that other CASA ADs have made mandatory. The AD’s effective date of 3 August 2006 is the binding timetable anchor, and the presence of optional inspection methods offers some limited operational choice in how inspections are performed, subject to the FAA AD’s acceptance criteria.