AD/BAe 146/52 Amdt 3 - Fuselage Frame 29

This AD rests on a small set of concrete technical and regulatory concepts. Each is stated in the AD text and used to determine inspection obligation and compliance outcomes.

• Applicability: The AD applies to “All Model BAe 146 Series aircraft; All BAe 146 RJ70 and RJ85 Series aircraft which do not have Modification HCM01411A, B, or C embodied, and All BAe 146 RJ100 Series aircraft which do not have Modification HCM01411A or B embodied.” The applicability therefore excludes airframes that have specific modifications embodied. Operators must check aircraft modification status against those Modification (HCM01411 series) identifiers to determine whether the AD applies.

• Service Bulletins: The AD mandates inspection in accordance with BAE Systems Service Bulletin SB 53‑130 or SB 53‑131 Revision 1, as applicable, or a later EASA approved revision. The SBs contain the threshold and repeat inspection timing (Table A in SB 53‑130 for BAe 146; Table 2 in SB 53‑131 Rev 1 for BAe 146 RJ). Only the SBs define the concrete intervals; the AD references them rather than reproducing the tables.

• Non‑Destructive Testing (NDT) technique: The AD recognises that a polymer coating on Frame 29 can prevent a thorough visual inspection. Where that is the case, it requires “the referenced surface eddy current inspection technique.” Eddy current testing is an NDT method suited to detecting cracks around bolt holes beneath coatings that hide visual cues. The AD makes the eddy current technique mandatory where coating obstructs visual inspection.

• Repair Instruction Leaflets (RILs): The AD identifies Repair Instruction Leaflet HC536H9159 and HC536H9168 as the documentation that, when fully embodied at each affected bolt position, cancels the requirement for repeat inspections. The RILs therefore define the substantive repair standard whose completion alters future inspection obligations.

• Threshold and Repeat Inspections: The AD uses the language “Unless already accomplished, at or before the ‘Threshold Inspection’ period … and thereafter at the ‘Repeat Inspection’ intervals specified …” That phrasing creates an initial deadline (threshold) and a recurring obligation (repeat intervals) until one of the terminating conditions is met. The terminating condition is full completion of the specified repairs at each affected bolt position.

• Regulatory linkage: The AD references prior foreign authority ADs (UK CAA AD 012‑05‑94 and AD 013‑03‑95) and allows later EASA approved service bulletin revisions. This shows the AD is tied to the broader airworthiness regulatory environment and to evolving approved documentation.

• Amendment logic: The AD is an amendment to an existing directive. Amendment 1 extended applicability to Avro 146 RJ aircraft, Amendment 2 responded to an update to the Requirement document (Non‑Destructive Testing Manual), and Amendment 3 emphasises eddy current inspection when coating impairs visual inspection. The original directive dates back to 22 June 1995.

Taken together, these concepts align the obligation to inspect with specific manufacturer documents, link the duration of repeated surveillance to the completion of specified repairs, and require the use of a specified NDT technique where visual inspection is obstructed. The precise compliance dates and intervals are not reproduced in the AD text but delegated to the tables in the referenced SBs. Operators therefore require access to those SBs and the named RILs to translate the AD into exact maintenance scheduling and scope of work.

The AD primarily affects a defined set of aircraft and the organisations responsible for their continuing airworthiness. The named affected parties and secondary stakeholders are:

• Aircraft operators of BAe 146 series aeroplanes: The applicability line applies to “All Model BAe 146 Series aircraft” and to BAe 146 RJ70, RJ85 and RJ100 Series aircraft that have not embodied specified modifications (HCM01411A, B or C for RJ70/RJ85; HCM01411A or B for RJ100). Operators must determine whether the AD applies to their fleet by checking modification embodiment status. For RJ variants, the presence of the listed modification(s) excludes the aircraft from the AD.

• Maintenance organisations and licensed engineers: The AD prescribes specific inspection techniques and repair instruction leaflets. Licensed maintenance organisations and engineers must implement inspections according to SB 53‑130 or SB 53‑131 Rev 1, perform surface eddy current testing where visual inspection is inadequate, and carry out repairs in accordance with the identified RILs if they aim to terminate repeat inspection obligations. They must also access and interpret the SB tables to determine threshold and repeat intervals.

• Continuing airworthiness managers and delegates: Personnel responsible for airworthiness compliance, including continuing airworthiness managers, planners and record-keepers, must schedule inspections at or before the threshold periods and plan for any repeat inspections until and unless the required repairs are completed at every affected bolt position. They must record compliance with the AD and associated SBs/RILs.

• Repair and component suppliers: Suppliers of repair parts, materials and tooling for the repair instruction leaflets (HC536H9159 or HC536H9168) will be implicated if operators choose to complete the repairs that cancel repeat inspection obligations. The AD refers specifically to repair instructions, so component supply chains must align with the RIL specifications.

• Regulators and delegated authorities: CASA (Civil Aviation Safety Authority) is the issuing authority, with the AD signed by a CASA delegate, David Villiers. The AD also references UK CAA ADs and accepts later EASA approved SB revisions, so national and international regulators and approval processes are relevant to compliance and documentation updates.

• Safety auditors and insurers: While not named in the AD, auditors and insurers will treat the AD as a mandatory airworthiness requirement for affected aircraft. Evidence of compliance or failure to comply affects airworthiness certification and potential insurance coverage.

• Operators of modified RJ aircraft: Aircraft that have embodied the listed modifications (HCM01411 series) are excluded from the AD for the RJ variants listed. That means modification embodiment status directly affects whether an operator must incur inspection workload or may rely on the modification to address the risk identified.

The AD therefore imposes obligations on operational and maintenance actors in the BAe 146 ecosystem. Who pays is primarily the operators, who must fund inspections, potential eddy current testing, and repairs. Who decides operationally is the operator together with their maintenance organisation, guided by the SB and RIL content. The AD points to manufacturer documentation and foreign ADs as informational inputs, and delegates regulatory authority to CASA via the signed directive.

The AD sets a series of explicit duties on operators and maintenance organisations, and records certain conditional rights or ends to duties. The duties and procedural rights are contained in the AD text and its references.

Key duties

• Inspect per specified service bulletins: Operators must “Inspect in accordance with BAE Systems Service Bulletin (SB) 53‑130 or SB 53‑131 Revision 1, as applicable; or later EASA approved service bulletin revision.” This is the principal duty and requires operators to obtain and follow the relevant SB content for method and scheduling.

• Use eddy current testing when visual inspection is obstructed: The AD states the polymer coating on Frame 29 “may prevent a thorough visual inspection. In this case, operators must utilise the referenced surface eddy current inspection technique.” That duty is conditional on the coating’s effect and mandates a specific NDT technique when visual inspection cannot be relied upon.

• Meet threshold and repeat timing: For BAe 146 aircraft the timing is “at or before the ‘Threshold Inspection’ period detailed in Table ‘A’ of SB 53‑130; and thereafter at the ‘Repeat Inspection’ intervals specified in Table ‘A’ of the service bulletin.” For BAe 146 RJ aircraft the timing is “at or before the ‘Threshold Inspection’ period detailed in Table 2 of SB 53‑131 Revision 1; and thereafter at the ‘Repeat Inspection’ intervals specified in Table 2 of the service bulletin.” The duty to inspect is therefore time‑bound and recurring until termination conditions are met.

• Apply Repair Instruction Leaflets to cancel repeats: The AD provides that “The requirement for repeat inspections is cancelled if the work has been fully completed at each affected bolt position as detailed in Repair Instruction Leaflet HC536H9159 or HC536H9168, as applicable.” If operators complete the RIL work at every affected bolt position, future repeat inspection obligations under the AD cease.

• Observe the “Unless already accomplished” wording: The AD repeatedly uses “Unless already accomplished” to indicate that if the specified action has already been performed, an operator does not need to repeat it to meet the AD. This creates a duty to demonstrate prior accomplishment through maintenance records where appropriate.

Conditional rights or effects

• Termination of repeat obligation: Operators have the conditional right to cease repeat inspections if they complete the RIL-specified work at each affected bolt position. The AD does not provide alternative ways to terminate repeats; only full completion per the named RILs is stated as sufficient.

• Acceptance of later EASA approved SB revisions: The AD permits compliance using “later EASA approved service bulletin revision[s].” That creates operational flexibility to use updated SB versions approved by EASA without requiring an additional AD amendment.

• Applicability exclusions: Operators of BAe 146 RJ aircraft that have embodied specified modifications (HCM01411A/B/C for RJ70/RJ85; HCM01411A/B for RJ100) are excluded from the AD. That functions as a categorical exemption where the modification addresses the issue.

Rights not enumerated in the text

• The AD does not state appeals processes, alternative compliance procedures, or explicit remedial rights in the event of disagreement. It also does not set out any permissions for alternative inspection methods beyond the surface eddy current technique where coating prevents visual inspection. Any deviation or alternative method would therefore need to rely on the normal regulatory approval processes outside this AD text.

Recordkeeping and evidence implications

• The AD’s “Unless already accomplished” provision and the repeat cancellation provision both imply a need for verifiable maintenance records showing the timing and content of inspections and the completion of RIL work. Operators and maintenance organisations must therefore maintain documentary evidence that inspections or repairs have been completed in accordance with the SBs and RILs to rely on the AD’s provisions.

Effective date and delegation

• The AD became effective on 16 February 2006 and is signed by a CASA delegate. That fixes the administrative start date for enforcement and compliance planning.

In short, the AD imposes inspection duties linked to SBs and requires eddy current testing where coatings prevent visual inspection. Completion of specified repair instructions at each affected bolt position eliminates the repeat inspection duty. The AD allows later EASA approved SB revisions to govern method and timing, and excludes aircraft that have embodied certain modifications from the AD’s scope.

The AD text does not specify criminal or administrative penalties, nor does it describe enforcement procedures or sanctions. The document itself is an airworthiness directive from CASA and sets mandatory technical obligations for affected aircraft, but it contains no penalty schedule or enforcement mechanisms within its text.

What the AD does show about enforcement context

• Regulatory instrument: The document is titled as an airworthiness directive (AD/BAe 146/52 Amdt 3) and is signed by a delegate of the Civil Aviation Safety Authority, David Villiers (22 December 2005). The issuance of an AD by CASA indicates the directive is a regulatory instrument intended to be complied with by operators of affected aircraft.

• Effective date: The AD “becomes effective on 16 February 2006.” The provision of an effective date establishes when the obligations become operative and therefore when compliance evidence is expected.

• Dependence on referenced documents: The AD bases its compliance obligations on BAE Systems Service Bulletins and Repair Instruction Leaflets and accepts later EASA approved SB revisions. Enforcement therefore is likely to focus on whether operators have followed the referenced SB and RIL procedures and met the threshold and repeat timing set out in those SBs. The AD’s content implies enforcement will be documentary and physical: inspectors will check maintenance records, SB/RIL embodiment and inspection reports, and possibly inspect physical evidence of repairs or inspections (including eddy current test records).

Not stated in text, but consequential observations relevant to enforcement risk and compliance burden

• No penalty clause in this AD text: Because the AD does not contain an express penalty clause, any enforcement action or sanctions for non‑compliance would depend on the broader statutory and regulatory framework under which CASA operates. The AD itself does not list fines, grounding authority or suspension mechanisms.

• Compliance evidence focus: The AD’s repeated references to “Unless already accomplished” and to specific SB tables and RIL completion at each affected bolt create clear documentary requirements. Enforcement will be practically exercised by verification of those records and by physical inspection outcomes. Operators should therefore expect compliance checks to focus on records demonstrating that thresholds were met, repeat inspections scheduled and performed, eddy current tests conducted where required, and RIL repairs completed where intended to terminate repeat inspections.

• International linkage: The AD references UK CAA ADs and accepts later EASA SB revisions. This cross‑recognition suggests that enforcement and evidence may draw on internationally recognised approved documentation and test methods.

Given the absence of explicit penalties in the AD text, readers should consult the statutory powers and civil aviation enforcement instruments under CASA and relevant civil aviation regulations to determine specific sanctions that may attach to non‑compliance in practice. Those instruments are not reproduced in the AD text and therefore are outside the source material for this document.

The AD explicitly connects to and depends upon other regulatory instruments and manufacturer documents rather than standalone statutory provisions within its own text. The AD references and interacts with several external documents and regulatory processes:

• Service Bulletins and EASA approvals: The AD requires inspection “in accordance with BAE Systems Service Bulletin (SB) 53‑130 or SB 53‑131 Revision 1, as applicable; or later EASA approved service bulletin revision.” That creates a direct interaction with manufacturer guidance and with EASA’s approval process. Changes to the SB approved by EASA will be accepted under the AD without an immediate further AD amendment, provided the revision is EASA approved.

• Repair Instruction Leaflets: The AD identifies Repair Instruction Leaflet HC536H9159 and HC536H9168 as the documents that, once fully embodied at each affected bolt position, cancel repeat inspection obligations. The AD therefore triggers a legal effect (termination of repeat inspection duty) conditional on completing the content of these RILs. That links the AD’s continuing obligations directly to the content of manufacturer repair documentation.

• UK CAA ADs: The AD notes “Note: UK CAA AD 012-05‑94 and AD 013‑03‑95 refer.” These references indicate an international regulatory cross‑reference; the UK CAA ADs contain related findings and perhaps parallel directives. The AD sits within an international airworthiness regime where national authorities may issue similar or linked ADs. Operators with international operations should therefore reconcile requirements across jurisdictions if they operate under multiple national airworthiness regimes.

• Non‑Destructive Testing Manual revision: Amendment 2 to the AD “responded to a revision of the BAe 146 (Avro) RJ aircraft Requirement document, which introduced the latest amendment of the Non‑Destructive Testing Manual.” That links the AD to the NDT Manual as an authoritative source for inspection technique standards. Changes to that manual therefore have implications for how the AD’s inspection obligations are interpreted and carried out.

• Modification embodiment effect: The AD’s applicability excludes aircraft that have embodied Modifications HCM01411A, B or C for certain RJ models. That creates a legal interaction between modification embodiment records and AD applicability. Aircraft maintenance records and modification embodiment status therefore have legal significance with respect to whether this AD applies to a given airframe.

• CASA regulatory framework: The AD is issued by CASA and signed by a delegate. While the AD itself does not state penalties, CASA’s broader regulatory powers and the Civil Aviation Regulations provide the enforcement framework that gives the AD operational force. Operators must therefore consider the AD within CASA’s statutory powers and the broader civil aviation regulatory regime.

• International approval and EASA: By accepting later EASA approved revisions of SBs, the AD allows the EASA approval process to affect compliance pathways. For operators outside EASA jurisdiction this means that EASA approvals are still the acceptable basis for revised SBs under this AD, highlighting cross‑authority recognition.

What the AD does not state about interactions

• The AD does not reproduce or quote the content of the SB tables, the RIL technical content, or the NDT Manual. Therefore the AD’s obligations are expressed by reference and convert into practical effect only when those external documents are consulted.

• The AD does not state how conflicts between documents are to be resolved, nor does it specify whether alternative methods of compliance may be accepted; such issues would be managed under CASA’s general procedures and the wider regulatory framework, not within this AD text.

In sum, the AD operates through reference to manufacturer SBs, repair instruction leaflets and internationally recognised approval processes (EASA and UK CAA ADs). Its practical interpretation and enforcement require access to and alignment with these external documents and the CASA regulatory framework.

The AD includes a concise amendment history embedded in its Background and heading information. The timeline and functional changes recorded in the AD text are:

• Original AD issuance: The AD states “The original issue of this airworthiness directive became effective on 22 June 1995.” That establishes the initial regulatory intervention related to Frame 29 cracking.

• Amendment 1: The Background records that “Amendment 1 included Avro 146 RJ aircraft in the inspection requirements of this Directive.” Functionally, Amendment 1 expanded the applicability of the AD to include the Avro 146 RJ family.

• Amendment 2: The Background explains that “Amendment 2 responded to a revision of the BAe 146 (Avro) RJ aircraft Requirement document, which introduced the latest amendment of the Non‑Destructive Testing Manual.” This indicates that Amendment 2 aligned the AD with a revised NDT Manual, implying updates to acceptable inspection techniques or standards.

• Amendment 3 (this Amendment): The AD is issued as “AD/BAe 146/52 Amdt 3” and is dated 2/2006. The Background states “Amendment 3 is issued to emphasise the requirement to accomplish an eddy current inspection of Frame 29 if the polymer coating does not allow a thorough visual inspection.” The text of the AD accordingly makes eddy current inspection mandatory where coating prevents visual inspection. The AD also bears a signature dated 22 December 2005 and an effective date of 16 February 2006.

• Cross‑references and prior ADs: The AD notes “UK CAA AD 012‑05‑94 and AD 013‑03‑95 refer.” These prior UK CAA ADs are recorded as relevant antecedent regulatory actions.

Administrative dates and references

• Signature: The AD is signed by David Villiers, Delegate of the Civil Aviation Safety Authority, on 22 December 2005.

• Effective date: “This Amendment becomes effective on 16 February 2006.” The AD’s administrative details therefore show a signature date in December 2005 and an operational start date mid‑February 2006.

Document identifiers

• The AD is identified as “AD/BAe 146/52 Amdt 3” with the date shorthand “2/2006” shown in the header tables.

Amendment drivers recorded in the text

• The recorded drivers for amendments are: initial discovery of cracking in fatigue specimens; the need to include RJ models (Amendment 1); updates to the Requirement document and NDT Manual (Amendment 2); and the need to emphasise eddy current inspection where polymer coating masks visual signs (Amendment 3). These drivers show a progression from discovery of a fatigue hazard through expansion of applicability and refinement of inspection technique requirements.

The AD text contains no further amendment provenance such as consultation records, cost-benefit analysis, or alternative compliance measures. Any further legislative or administrative amendment history beyond what is recorded in the AD text is not included in the source material provided.

The provided AD text contains no litigation history, no reference to judicial decisions, and no mention of disputes, challenges, or court proceedings arising from this AD or its prior iterations. The Background and amendment notes describe technical and administrative developments only.

Implications of the absence of litigation history in the text

• No judicial precedents cited: The AD does not cite any court decisions or administrative reviews. Therefore the source provides no direct evidence of challenges to the AD’s legal validity or of litigation over its interpretation or enforcement.

• Operational context for research: To determine whether litigation has occurred, or whether legal challenges or enforcement actions were taken in relation to this AD, one would need to search external sources such as CASA enforcement records, tribunal or court databases, industry legal reporting, or operator records. Those sources are outside the AD text and therefore not reflected in this document.

• Evidence of dispute or contestation: The absence of litigation references within the AD is not evidence that none occurred; it simply reflects that the AD document itself does not contain litigation annotations. ADs typically do not include litigation history as part of their text.

What a practitioner should consider when looking beyond the AD text

• Check CASA enforcement and administrative records: If a practitioner needs to know whether compliance disputes or enforcement sanctions occurred, the CASA enforcement registry or public notices may contain relevant cases.

• Review judicial and tribunal databases: Appeals or judicial reviews, if any, are recorded in court and tribunal records which are not part of the AD.

• Consult operator maintenance records and insurance claims: Enforcement action may result in administrative settlements, remedial works, or insurance claims. Those may be recorded in operator files or industry safety reports.

• International interactions: Because the AD references UK CAA ADs and EASA approvals, potential litigation or regulatory divergence may be recorded in UK or EASA administrative records rather than solely within Australian records.

Because the source material does not include litigation history, this section cannot state any cases or outcomes. Practitioners requiring litigation or dispute history must consult external legal and regulatory databases.

The AD contains specific technical and procedural features that create practical pitfalls for operators and maintainers. These “gotchas” derive directly from the AD text.

• Applicability hinges on modification embodiment codes: The AD applies to all BAe 146 series aircraft and to certain RJ variants only if they do not have specified modifications embodied. For RJ70 and RJ85 the exclusion applies where Modification HCM01411A, B, or C has been embodied; for RJ100 the exclusion applies where HCM01411A or B has been embodied. Operators must verify modification embodiment against maintenance and modification records. Misidentifying an aircraft as inapplicable because of a mistaken modification record will expose the operator to non‑compliance risk.

• Key compliance content is in external SB tables: The AD does not reproduce the ‘Threshold Inspection’ or ‘Repeat Inspection’ intervals. It directs operators to Table A of SB 53‑130 for BAe 146 and Table 2 of SB 53‑131 Rev 1 for BAe 146 RJ. That means the AD’s scheduling obligations cannot be implemented without accessing the exact SB tables. Failure to consult the SB could lead to incorrectly timed inspections.

• Polymer coating that impedes visual inspection triggers mandatory eddy current testing: The AD emphasises that “The polymer coating on Frame 29 may prevent a thorough visual inspection. In this case, operators must utilise the referenced surface eddy current inspection technique.” Operators must therefore not rely on superficial visual checks where coating is present; they must have eddy current capability or contract a provider. Assuming visual inspection is sufficient when coating is present would be non‑compliant.

• Repeat inspections can be cancelled only by full completion at each affected bolt position: The AD does not allow partial repair scope to cancel repeat inspections. It requires that “the work has been fully completed at each affected bolt position as detailed in Repair Instruction Leaflet HC536H9159 or HC536H9168, as applicable.” Skipping bolt positions or partial embodiment of the RIL will not meet the AD’s termination condition.

• The RIL identifier matters: Two different RILs are named (HC536H9159 and HC536H9168). Operators must confirm which RIL is applicable to their aircraft/build and ensure the correct RIL’s work is fully embodied. Using the wrong RIL, or misapplying RIL content, may not satisfy the AD.

• “Unless already accomplished” wording imposes recordkeeping obligations: The AD allows relief for work “already accomplished.” To rely on that you must have verifiable maintenance records showing that the inspection or repair was performed to the SB/RIL standards. Incomplete or unverified records may not be accepted as proof of prior accomplishment.

• AD accepts later EASA approved SB revisions: The AD permits “later EASA approved service bulletin revision[s]”. Operators should ensure that any later SB revision relied upon is actually EASA approved; manufacturer-only revisions without EASA approval may not meet the AD’s acceptance criteria.

• Discrepancy between signature and effective date: The AD is signed on 22 December 2005, but becomes effective on 16 February 2006. Operators should not assume compliance obligations began immediately on signature; the official effective date is 16 February 2006.

• International cross‑references: The AD includes a note referring to UK CAA AD 012‑05‑94 and AD 013‑03‑95. Operators should review those CAA ADs for additional context and technical detail that may bear on inspection technique or scope, particularly if operating internationally.

• The AD does not set out inspection technique parameters: While it requires eddy current inspection where coating prevents visual inspection, the AD does not translate the NDT technique into specific equipment calibrations, probe types, acceptance criteria or reporting formats. Those details are expected to be in the SBs or the NDT Manual. Operators must obtain those documents to ensure inspections meet the AD’s intent.

• No penalty text: The AD contains no penalty clause. That does not relieve the operator of mandatory compliance; however practitioners should consult CASA’s enforcement framework if they need to know specific sanctions for non‑compliance. Relying on the absence of penalty language within the AD itself would be a mistake.

• Repair suspension affects future inspection burden: Completing the RIL work at each affected bolt position cancels repeat inspections. Operators must weigh the one‑off cost and downtime of completing full repairs against the ongoing cost of repeat inspections; this is a practical trade‑off that the AD frames but does not quantify.

These points are practical, source‑grounded risks and pitfalls. Each arises directly from the AD text and the way it delegates technical detail to service bulletins and repair instruction leaflets.

The AD sets out inspection and repair obligations by reference to manufacturer documents. Below is a stepwise compliance checklist based on the AD text; it assumes access to the SBs and RILs named in the AD.

1. Confirm applicability

   • Check fleet records to confirm whether each airframe is a BAe 146 series, or an RJ70, RJ85 or RJ100 variant.
   • For RJ70 and RJ85, determine whether Modification HCM01411A, HCM01411B or HCM01411C has been embodied. If any of these modifications are embodied the AD does not apply to that airframe.
   • For RJ100, determine whether Modification HCM01411A or HCM01411B has been embodied. If any of these are embodied the AD does not apply to that airframe.
   • Document the modification status in the maintenance record as the applicability determination is a compliance gate.

2. Obtain the referenced documents

   • Obtain BAE Systems Service Bulletin SB 53‑130 (for BAe 146) or SB 53‑131 Revision 1 (for BAe 146 RJ), as applicable.
   • Confirm whether any later EASA approved SB revisions exist. The AD permits use of later EASA approved revisions; ensure the revision is EASA approved.
   • Obtain Repair Instruction Leaflet HC536H9159 and HC536H9168 and determine which is applicable to your airframe configuration.
   • If necessary, obtain the BAe 146 (Avro) RJ Requirement document and the Non‑Destructive Testing Manual referenced indirectly by Amendment 2.

3. Schedule threshold inspection

   • Using Table A in SB 53‑130 (BAe 146) or Table 2 in SB 53‑131 Rev 1 (BAe 146 RJ), identify the ‘Threshold Inspection’ period for your airframe.
   • Unless the inspection has “already [been] accomplished” in accordance with the SB, schedule and perform the inspection at or before the threshold period identified in the SB table.

4. Perform inspections using specified techniques

   • Conduct the inspection in accordance with the SB procedural content. The SB will contain the inspection method, inspection areas, and reporting requirements.
   • If during inspection the polymer coating on Frame 29 prevents a thorough visual inspection, perform the “referenced surface eddy current inspection technique” as directed by the SB and NDT Manual. Ensure eddy current equipment and personnel qualifications meet the SB or NDT Manual specifications.

5. Maintain inspection interval discipline

   • After the threshold inspection, perform repeat inspections at the intervals specified in the SB table (Repeat Inspection intervals).
   • Maintain maintenance records showing the dates, findings, and any corrective action taken for each inspection.

6. Decide on repairs that cancel repeat inspections

   • If the operator elects to remove the repeat inspection obligation, plan to accomplish the work “fully completed at each affected bolt position as detailed in Repair Instruction Leaflet HC536H9159 or HC536H9168, as applicable.”
   • Confirm whether the chosen RIL is applicable to the aircraft model and configuration. The AD requires full completion at each affected bolt position; partial application is not sufficient.

7. Document RIL embodiment

   • After RIL work is completed, document in the aircraft maintenance records that the RIL work has been fully completed at each affected bolt position per HC536H9159 or HC536H9168.
   • Record the work package, parts used, work order references, and signatory evidence of conformity.

8. Retain and present records for verification

   • Keep all inspection reports, eddy current test results, repair records and parts traceability documentation in the aircraft’s maintenance record package.
   • Be prepared to present these records during CASA audits, surveillance, or airworthiness reviews.

9. Use later EASA approved SB revisions where applicable

   • If you rely on a later SB revision, confirm EASA approval status and document that the later revision is EASA approved. Follow the revision content in place of the earlier SB.

10. Timing considerations

    • Note the AD effective date: 16 February 2006. For historical compliance issues, be prepared to show that threshold or repeat inspections were performed timely relative to the SB tables and the AD effective date.
    • If work was “already accomplished” before the AD effective date, ensure the records show conformity with the SB methodology or acceptable equivalent as the AD’s “Unless already accomplished” language requires demonstrable accomplishment.

11. Manage operational trade‑offs

    • Evaluate the cost and downtime of completing the RIL‑specified repairs at every affected bolt position against the ongoing burden of periodic repeat inspections. This is a maintenance strategy choice permitted by the AD’s termination provision.

12. Consult regulators for alternative methods or clarifications

    • The AD does not discuss alternative methods of compliance or the approval process for deviations. If an operator wishes to propose an alternative inspection technique or repair method not expressly covered by the SB or RIL, consult CASA through established alternative method of compliance channels.

13. International operations and cross‑reference checks

    • If operating internationally, reconcile the AD with UK CAA AD 012‑05‑94 and AD 013‑03‑95 (both referred to in the AD) and with any jurisdictional equivalents. Ensure inspection and repair work meets all applicable regulatory expectations in the jurisdictions of operation.

14. Ensure competent personnel and equipment for eddy current testing

    • Where eddy current inspection is required due to polymer coating, ensure that suitably qualified NDT technicians and calibrated eddy current equipment are used, and that the test reports meet the SB and NDT Manual acceptance criteria.

Compliance is therefore a function of confirming applicability, obtaining the referenced SBs and RILs, performing the threshold and repeat inspections (including eddy current testing where necessary), and documenting either the ongoing inspection regime or the full RIL repairs that cancel repeat inspections. The AD gives operators the option to stop repeat inspections by doing the RIL work, but operators must ensure that the work is “fully completed at each affected bolt position” and documented accordingly.