The AD rests on a small set of technical and procedural concepts that determine compliance obligations.

Applicability scope: The AD applies to Learjet Model 35/35A/36/36A aircraft only where the aircraft serial numbers appear in Bombardier SB 35/36-51-3 and SB 35/36-51-4 Revision 1 or Revision 2. The AD therefore operates by reference to manufacturer service bulletins for applicability lists, rather than reproducing serial numbers in the AD text.

Inspections: The AD mandates two layers of inspection for the forward engine beam shear web:

• a detailed inspection using a probe (Requirement 1), and
• a general visual inspection (also Requirement 1, with follow-on in Requirement 3).

The term "detailed" inspection is operationalised by the AD through reference to the Bombardier SB 35/36-51-3 Accomplishment Instructions. The AD also specifies the use of a probe for the detailed inspection and requires modification of drag angles as part of the inspection activity.

Quantitative trigger metric: The AD introduces an electrical resistance measurement as a diagnostic metric during the detailed probe inspection. The metric is expressed in milliohm with two threshold bands that determine follow-on repairs or repeated inspections:

• less than 0.110 milliohm: the inspections required by Requirement 1 must be repeated;
• 0.110 milliohm or more but less than 0.150 milliohm: repair and modification per SB 35/36-51-4 (Rev 1 or Rev 2);
• 0.150 milliohm or more: repair and modification per SB 35/36-51-4 (Rev 1 or Rev 2) (Requirement 2).

Crack-size trigger: The general visual inspection includes a size threshold for crack openings. If any crack opening is more than 0.030-inch, the AD requires following particular subsections of the SB 35/36-51-3 (paragraphs 2.C.(16)(a) and 2.C.(16)(b)), repair by a method approved by the FAA Manager at the Wichita ACO, and accomplishment of the terminating action specified in Requirement 4 (Requirement 3).

Delegated substantive detail: The AD delegates substantive procedural steps to Bombardier SBs and, for certain non-standard repairs, to the FAA Manager (Wichita ACO). The AD therefore functions as a regulatory overlay mandating adherence to the SB content and potentially requiring FAA ACO approval for specific repair methods.

Reference dates and revisions: The AD specifies the date of SB 35/36-51-3 as 1 February 2001, and SB 35/36-51-4 Revision 1 as 2 August 2001 and Revision 2 as 6 December 2001. These dates are used to identify the precise SB versions to be followed where those revisions are referenced.

Missing elements in the supplied text: The supplied AD text references a compliance section and a Requirement 4 (terminating action) but does not reproduce them. The AD preamble highlights that the required action must be taken "at the time mentioned in the compliance section", but the compliance timing is absent from the supplied text. Similarly, Requirement 4 is referenced as containing the terminating action after certain repairs, but its text is not present here. These absences mean the supplied AD text delegates timing and the final terminating action to other parts of the AD not included in the supplied extract, and to the Bombardier SBs.

Owners and operators of Learjet Model 35, 35A, 36 and 36A aircraft whose serial numbers are listed in the cited Bombardier Service Bulletins are the primary parties affected. The AD's Applicability section limits the directive to aircraft with serial numbers listed in SB 35/36-51-3 and SB 35/36-51-4 Revision 1 or Revision 2. Therefore, possession of the SBs is necessary to determine whether an individual aircraft falls within the AD's scope.

Maintenance organisations and certified maintenance personnel are directly affected because the AD prescribes specific inspection techniques (a detailed probe inspection and a general visual inspection) and specific repair/modification procedures to be performed in accordance with the Bombardier SB Accomplishment Instructions. The AD requires use of a probe during the detailed inspection (Requirement 1), measurement of electrical resistance in milliohm during that inspection (Requirement 2), and the execution of repairs per SB 35/36-51-4 Revision 1 or Revision 2 where indicated. These are tasks normally carried out by approved maintenance organisations, licensed engineers or technicians; they therefore incur the labour, tooling and record-keeping obligations associated with AD compliance.

Parts suppliers and repair stations are affected to the extent the repairs and modifications prescribed by SB 35/36-51-4 require replacement parts, modifications to the forward engine beam shear web, or specialised tooling. The AD requires repair and modification "in accordance with the Accomplishment Instructions" of the SBs (Requirements 2.b, 2.c and 3), which may specify parts, processes and documentation that affect supply chains and stockholding.

Regulatory/approval authorities are affected in places where the AD delegates approval: where the AD requires repair "per a method approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA", the FAA Wichita ACO plays an approval/oversight role for those particular repair methods (Requirement 3). CASA is the issuing authority (the AD is issued under subregulation 39.1(1) of CASR 1998 and signed by a CASA delegate). The text shows a multijurisdictional interaction in approval and method sign-off: the AD requires adherence to Bombardier SBs and in some cases FAA ACO approval.

Insurers and lessors may be indirectly affected because the AD creates mandatory inspection and repair obligations that can affect aircraft availability and airworthiness status. Non-compliance with an AD typically has implications for continued airworthiness; the AD requires that the specified action be taken "in relation to the aircraft or aeronautical product mentioned in the applicability section", and at the times set out in the compliance part of the AD (preamble). The supplied text does not reproduce the compliance timing, but it does make clear that follow-up and terminating action are integral to satisfying the AD.

Finally, accident investigators and safety managers are marginally affected because the AD alters the maintenance regime for the forward engine beam shear webs , a structure related to engine mounting , and prescribes inspection thresholds and escalation paths for cracking and electrical resistance, potentially altering failure modes and maintenance records.

The AD imposes specific duties on the operator/maintenance organisation of each applicable aircraft and establishes points of delegation to Bombardier SBs and the FAA Manager for repair approvals.

Primary duties imposed by the AD:

• Perform a detailed inspection using a probe and a general visual inspection of the forward engine beam shear webs, including modification of the drag angles, in accordance with the Accomplishment Instructions of Bombardier SB 35/36-51-3, dated 1 February 2001 (Requirement 1). This is a direct, mandatory duty.

• Measure resistance during the detailed inspection and act according to the measured value (Requirement 2). The AD specifies three outcome bands with attendant obligations:

  • If resistance < 0.110 milliohm, repeat the inspections required by Requirement 1.
  • If resistance ≥ 0.110 milliohm but < 0.150 milliohm, repair and modify per SB 35/36-51-4 Revision 1 (2 Aug 2001) or Revision 2 (6 Dec 2001).
  • If resistance ≥ 0.150 milliohm, repair and modify per SB 35/36-51-4 Revision 1 or Revision 2.

• After the general visual inspection (Requirement 1), accomplish the applicable follow-on actions listed in SB 35/36-51-3 (Requirement 3). If any crack opening discovered during the general inspection is more than 0.030-inch, follow SB 35/36-51-3 paragraphs 2.C.(16)(a) and 2.C.(16)(b), repair per a method approved by the Manager, Wichita ACO, FAA, and accomplish the terminating action specified in Requirement 4 (Requirement 3).

Delegated duties and rights:

• The AD requires adherence to Bombardier SBs for inspection, repair and modification methods, and thereby delegates procedural detail to the manufacturer’s Accomplishment Instructions. That creates a duty to obtain and follow the SB content specified (SB 35/36-51-3 and SB 35/36-51-4 Rev 1 or Rev 2).
• For repairs associated with cracks exceeding 0.030-inch, the AD requires that repair be performed "per a method approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA." That gives the FAA Wichita ACO authority (a right or discretionary power) to approve particular repair methods. Operators seeking such approval must therefore interact with the FAA Manager at Wichita ACO.

Rights and constraints implicit in the AD:

• The AD does not itself authorise alternative methods of compliance in the supplied text; it prescribes the SB procedures and notes FAA Manager approval for certain repairs. The rights of the operator to seek alternative methods of compliance, or to request an extension or variation, are not set out in the supplied extract. The supplied AD does not reproduce any procedural mechanism for applying for an alternative method of compliance, nor does it reproduce a compliance deadline or extension mechanism; those elements may be contained in the full AD outside the supplied text.
• The AD requires a terminating action identified in Requirement 4 after certain repairs, but Requirement 4's text is not supplied. The operator’s duty to accomplish that terminating action is therefore stated but the content of that action and any mechanics remain unspecified within the extract provided.

Record-keeping and certification duties: Although not reproduced explicitly in the supplied text, ADs generally require that mandated inspections and repairs be recorded to show compliance. The supplied text establishes an obligation to perform the inspections and repairs "in accordance with" Bombardier SBs; operators and maintenance organisations will need to maintain records demonstrating that those SB procedures were followed and that any FAA Manager-approved repair method was obtained and documented, because the AD makes these actions mandatory.

The supplied AD text establishes the regulatory basis and sets out the mandatory actions, but the extract does not reproduce enforcement penalties, specific sanction provisions, or administrative enforcement procedures. The preamble states that the AD is issued under subregulation 39.1(1) of CASR 1998, which is identified as the legal foundation for CASA to issue ADs; the AD requires action "in relation to the aircraft or aeronautical product mentioned in the applicability section" and "at the time mentioned in the compliance section." The supplied text does not include express penalty clauses or enforcement mechanisms.

Enforcement framework implied by the text:

• The AD is a regulatory instrument issued by CASA under an identified subregulation. That identifies CASA as the issuing authority and implies that compliance is mandatory under the regulatory framework referenced (subregulation 39.1(1) of CASR 1998). The AD itself imposes duties which, under the broader regulatory scheme, would typically be enforceable by CASA as regulator. The supplied extract does not set out the specific enforcement actions CASA may take in the event of non-compliance, nor does it reproduce any civil or administrative penalty schedules, suspension mechanisms or grounding powers.

Mechanics of enforcement implied by AD structure:

• The AD prescribes actions to be taken "in accordance with" Bombardier SBs and requires FAA Manager approval for certain repairs; failure to follow those instructions would leave the aircraft outside the AD’s compliance requirements and therefore potentially not airworthy under the prevailing regulatory regime. The supplied text does not specify the process for CASA to verify compliance, nor does it state the administrative steps to be taken if an operator fails to comply.

Interaction with approval authorities:

• For repairs requiring FAA Manager approval, enforcement regarding those repairs may involve the FAA’s approval records as evidence of compliant repair methods. The AD requires that certain repairs be "per a method approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA" (Requirement 3). That cross-references FAA oversight in the validation of repair methods; the supplied text does not describe how CASA will treat FAA approval records for enforcement, but the AD makes FAA approval an element of compliance.

Limitations of the supplied extract:

• The supplied extract does not contain an explicit penalties section, civil penalty amounts, criminal sanctions, administrative fine provisions or compliance monitoring procedures. To understand the full enforcement regime that accompanies this AD, including any consequences for non-compliance, one must consult the complete AD text and the relevant provisions of CASR 1998 cited in the preamble (subregulation 39.1(1)), which are not reproduced in the present extract.

The AD explicitly references and is issued under subregulation 39.1(1) of the Civil Aviation Safety Regulations (CASR) 1998. That reference establishes the AD as a regulatory instrument operating within the CASR framework. The supplied text does not reproduce the text of subregulation 39.1(1) itself; it instead states that the AD is issued under that subregulation. Practically, that means the AD is intended to be part of a broader scheme of airworthiness regulation where CASA has the power to require corrective action to address unsafe conditions.

Interaction with manufacturer service documents:

• The AD operates by requiring compliance with manufacturer-issued service bulletins: Bombardier SB 35/36-51-3 (dated 1 February 2001) and SB 35/36-51-4 Revision 1 (2 August 2001) or Revision 2 (6 December 2001). The AD therefore creates a legal obligation to carry out the procedures set out in those SBs for aircraft to which the AD applies. This is an example of statutory regulation incorporating private technical documents by reference for procedural detail.

Interaction with FAA approvals:

• The AD requires that certain repairs be performed "per a method approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA" (Requirement 3). That creates an interaction between CASA’s AD and FAA approvals, with the FAA Wichita ACO having approval authority for specified repair methods. The supplied text does not detail how CASA will treat FAA approvals or how FAA approval filings interact with CASA records, but it explicitly requires FAA Manager approval where the SB escalation path so directs.

Implications for continuing airworthiness and certification:

• The AD’s mandatory inspections and repairs are components of an aircraft's continuing airworthiness obligations. Compliance, as required by the AD, is a condition of continuing to operate the affected aircraft within the regulatory regime. The supplied text references that the AD "requires that the action set out in the requirement section ... be taken in relation to the aircraft ... in the circumstances mentioned ... and at the time mentioned in the compliance section." Compliance timing and the nature of the terminating action are therefore material to certification and airworthiness, but the supplied extract does not reproduce the compliance schedule.

No express external conflicts in supplied text:

• The supplied AD extract does not identify conflicts or interactions with other specific statutory provisions beyond the CASR reference, nor does it refer to other ADs or regulatory waivers. Any interaction with workplace health and safety laws, contract law, or insurance law is not specified in the supplied text; such interactions would arise in practice but are not described here.

Requirement to follow SB revisions by date:

• The AD specifies precise SB revision dates. Where SB 35/36-51-4 is required, the AD identifies Revision 1 dated 2 August 2001 and Revision 2 dated 6 December 2001 as acceptable references. That fixes which manufacturer instructions form part of the regulatory requirements. The supplied text does not authorise following later or earlier revisions, nor does it set out a mechanism to approve alternate SB revisions; operators must follow the versions identified in the AD unless an alternative method of compliance or different approval process is set out elsewhere in the full AD or obtained through the relevant authority.

The supplied AD extract carries identifiers that locate it in time and context, and it cites specific service bulletin dates and revisions. The AD is captioned "AD/LEARJET 35/39 Forward Engine Beam Shear Web 5/2004" and the repeated header identifies the AD as AD/LEARJET 35/39 Forward Engine Beam Shear Web 5/2004. The Bombardier Service Bulletins referenced in the AD are dated and some are noted with revision dates: SB 35/36-51-3 is dated 1 February 2001; SB 35/36-51-4 Revision 1 is dated 2 August 2001; SB 35/36-51-4 Revision 2 is dated 6 December 2001.

Beyond those SB dates and the AD identifier (5/2004) present in the supplied text, the extract does not contain a legislative amendment record or a history of prior or subsequent amendments to the AD. The supplied extract does not reproduce any amendment log, superseding ADs, or revocation language. It similarly does not record whether earlier versions of the AD were issued, whether the AD supersedes prior ADs, or whether it has been amended since initial issuance. The supplied extract contains the AD heading and the Requirements but omits any explicit amendment chronology.

Practical consequence for users: To obtain a full amendment history, affected parties will need to consult the complete AD file as issued by CASA, which typically records dates of issuance, any amendments, supersessions, or cancellations. The supplied text gives only the AD identifier and the SB revision dates; it does not itself provide a comprehensive amendment history. Any determination about whether the AD has been superseded, amended, or remains in force must therefore be made by consulting the issuing authority's records or the full AD document.

The supplied AD extract does not cite, reference, or otherwise include any litigation history, cases, or adjudications. It names no court decisions, administrative appeals, or judicial reviews associated with this AD. The text does not list any proceedings challenging the AD itself, nor does it reference determinations by courts or tribunals about its content or validity.

Because the extract contains no litigation references, there are no case names to report from the supplied source. Any assertion about existing litigation or the outcome of challenges would require consultation of external records or legal databases, which are not part of the supplied AD text.

For practitioners seeking precedent or dispute history connected to the AD, the absence of litigation references in the supplied text means that the next step is to search CASA records, FAA records (insofar as FAA approvals are implicated), and jurisdictional court or tribunal databases for any proceedings that relate specifically to AD/LEARJET 35/39 Forward Engine Beam Shear Web 5/2004 or the underlying SBs. The supplied extract itself provides no litigation narrative.

The supplied AD extract contains several operational and interpretative points that can cause compliance confusion if read in isolation. These are documented below with references to the relevant Requirement paragraphs.

1. Applicability is by serial number list contained in the Bombardier SBs, not reproduced here. The AD applies only to Models 35, 35A, 36, and 36A aircraft "with serial numbers listed in Bombardier Service Bulletins 35/36-51-3, and 35/36-51-4 Revision 1 or Revision 2." That means an operator cannot determine applicability from the AD text alone unless they have the SBs; failing to check the SBs risks misreading whether a specific airframe is subject to the AD.

2. Key elements of the AD are delegated to the Bombardier SBs. The AD repeatedly requires actions "in accordance with" the Accomplishment Instructions of SB 35/36-51-3 and SB 35/36-51-4 Rev 1 or Rev 2. Relying on the AD text alone is insufficient; the SBs contain the technical procedures, tooling, and step sequences that must be followed.

3. The resistance-measurement metric is specified in milliohm with narrow thresholds that determine materially different follow-on actions. The AD mandates measurement during the probe inspection and sets three zones (<0.110 mΩ; ≥0.110 and <0.150 mΩ; ≥0.150 mΩ). Practitioners must ensure measurement equipment is calibrated and capable of accurate measurement at milliohm resolution. The supplied extract does not specify measurement method or equipment tolerances; these are likely in the SBs. If an operator uses instrumentation that yields different results due to technique, there is a risk of misclassifying the condition and applying the wrong follow-on action.

4. Ambiguity in the "repeat the inspections" instruction. For resistance less than 0.110 milliohm, Requirement 2.a says "repeat the inspections required by Requirement 1." The supplied text does not specify the interval for repeating such inspections (for example, repeat after a set number of hours, cycles, or calendar time). The compliance section , which would typically set inspection intervals , is not included in the supplied extract. Absent the compliance timing, there is ambiguity about how often the repeat inspections must be performed.

5. Missing Requirement 4 in the supplied extract. Requirement 3 indicates that, for crack openings greater than 0.030-inch, the operator must "accomplish the terminating action specified in Requirement 4." The supplied extract does not include the text of Requirement 4, leaving unclear what the terminating action is. Without Requirement 4 the operator cannot verify what action will formally close out the AD requirement for those cases.

6. Cross-jurisdiction repair approval. The AD requires repair "per a method approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA" for certain crack conditions (Requirement 3). That means at least in those circumstances the FAA Wichita ACO must approve the repair method. Depending on the operator’s regulatory environment, this cross-jurisdictional approval step could add procedural delay, require supplementary documentation, or raise questions about whether CASA acceptance is separately required. The AD does not state the process or timing for obtaining that FAA approval in the supplied text.

7. Dependence on precise SB revisions and dates. Where the AD requires SB 35/36-51-4 Revision 1 or Revision 2, it anchors the repair procedures to specific document versions (dated 2 Aug 2001 and 6 Dec 2001 respectively). Operators must ensure they follow the exact revision specified. The supplied text does not state whether later revisions, amendments or letters are acceptable; the AD as provided will usually only accept the versions it cites unless an alternative method of compliance or revised AD provides otherwise.

8. Crack-size threshold of 0.030-inch. The AD imposes a specific crack opening threshold expressed in inches (0.030-inch) for escalation. Practitioners must ensure consistent measurement practice to determine whether an observed crack exceeds that dimension; the supplied extract does not include measurement method or locale for the measurement, which may be detailed in the SBs.

9. The AD incorporates manufacturer instructions but does not replicate SB content. Operators must obtain the Bombardier SBs to know the exact inspection method, probe technique, repair steps, necessary parts, or modification instructions. Failure to consult the SBs will leave gaps in actionable detail.

10. No compliance schedule in the supplied extract. The AD preamble and Requirement references indicate actions must occur "at the time mentioned in the compliance section", but that compliance section is not included in the supplied extract. This omission is a practical "gotcha": an operator cannot determine deadlines or intervals solely from the text provided here.

11. Possible uncertainty over what constitutes the "terminating action." The AD references "the terminating action specified in Requirement 4." Without Requirement 4 text, operators will be uncertain whether the repair and modification steps described elsewhere will end the AD's obligations or whether additional inspections or records are required. Operators must locate Requirement 4 in the full AD.

12. Multi-document compliance trail. Demonstrating compliance likely requires combining evidence from the AD, the Bombardier SBs, any FAA approvals obtained for alternative repair methods, and maintenance records. Gaps among these documents (for example, SB versions, dates, or absence of FAA approval documentation) will complicate audit or inspection by regulators.

To comply with the AD as supplied, operators and maintenance organisations should follow this structured sequence based on the AD’s Requirements and the SB references. Note that the supplied extract omits the compliance timing and Requirement 4; those items must be obtained from the full AD document. The steps below set out the actions the AD requires, with references to the relevant Requirements.

1. Confirm applicability

• Obtain Bombardier Service Bulletin 35/36-51-3 (dated 1 February 2001) and Bombardier Service Bulletin 35/36-51-4 Revision 1 (2 August 2001) and Revision 2 (6 December 2001).
• Check whether the aircraft serial number is listed in those SBs. The AD’s Applicability is limited to Model 35, 35A, 36 and 36A aircraft with serial numbers listed in those SBs. Do not assume applicability based on model alone; the serial number lists in the SBs determine whether the AD applies.

2. Obtain the Accomplishment Instructions

• For any aircraft identified as applicable, obtain and review the Accomplishment Instructions in SB 35/36-51-3 and SB 35/36-51-4 Rev 1 or Rev 2, since the AD requires inspections and repairs "in accordance with" those instructions (Requirement 1 and Requirements 2.b/2.c/3).
• Ensure the SB versions and dates match those specified in the AD: SB 35/36-51-3 dated 1 February 2001; SB 35/36-51-4 Rev 1 dated 2 August 2001; SB 35/36-51-4 Rev 2 dated 6 December 2001.

3. Perform the detailed probe inspection and general visual inspection

• Carry out the detailed inspection using a probe and the general visual inspection of the shear webs of the forward engine beams (including modification of the drag angles) in accordance with the Accomplishment Instructions of SB 35/36-51-3 (Requirement 1).
• As part of the detailed probe inspection, measure electrical resistance as specified in the SB and the AD (the AD requires a resistance measurement in milliohm during the probe inspection , Requirement 2).

4. Interpret resistance measurements and take follow-on actions

• If the measured resistance is less than 0.110 milliohm, repeat the inspections required by Requirement 1 (Requirement 2.a). Because the supplied extract does not contain the compliance timing, consult the full AD compliance section to determine the interval and any scheduling for repeated inspections.
• If the measured resistance is 0.110 milliohm or more but less than 0.150 milliohm, perform repair and modification of the forward engine beam shear web in accordance with the Accomplishment Instructions of SB 35/36-51-4 Revision 1 or Revision 2 (Requirement 2.b).
• If the measured resistance is 0.150 milliohm or more, perform repair and modification in accordance with SB 35/36-51-4 Revision 1 or Revision 2 (Requirement 2.c).

5. Follow-up after the general visual inspection

• After the general visual inspection required by Requirement 1, accomplish the applicable follow-on actions specified in the Accomplishment Instructions of SB 35/36-51-3 (Requirement 3).
• If any crack opening found during the general inspection is more than 0.030-inch, follow SB 35/36-51-3 paragraphs 2.C.(16)(a) and 2.C.(16)(b), repair per a method approved by the Manager, Wichita ACO, FAA, and accomplish the terminating action specified in Requirement 4 (Requirement 3). To do this:
  • Document the crack opening measurement (ensure measurement technique is consistent with SB guidance).
  • Notify and submit any required documentation to the Manager, Wichita ACO, FAA, seeking approval for the proposed repair method if required by the SB paragraphs.
  • Obtain written approval from the Manager, Wichita ACO, FAA, for the repair method before performing the repair if the SB requires FAA approval.
  • After repair, complete the terminating action specified in Requirement 4 (locate Requirement 4 in the full AD to determine the specific terminating action).

6. Record-keeping and evidence

• Maintain maintenance records showing inspection dates, measurement readings (milliohm values), photos or diagrams of crack locations and sizes (including measurements exceeding 0.030-inch if any), details of repairs and modifications performed in accordance with SB 35/36-51-4 Rev 1 or Rev 2, and any FAA Manager approvals obtained.
• Ensure that records reference the exact SB revision used and that repair documentation references the FAA Wichita ACO approval when applicable.

7. Equipment, competency and calibration

• Use measurement equipment capable of reliably reading electrical resistance at the milliohm level. Ensure instruments are calibrated and that personnel are trained in the measurement technique specified by the SBs (the AD requires resistance measurement in milliohm , Requirement 2).
• Ensure maintenance personnel performing the probe and visual inspections are trained to the level necessary to follow the SB Accomplishment Instructions.

8. Verify the compliance schedule

• Obtain the full AD text (including the compliance section and Requirement 4) from CASA and confirm the required timing for initial inspections and any repetitive intervals. The supplied extract notes that actions must be taken "at the time mentioned in the compliance section" but that section is not included here.

9. Seek clarification or alternative method of compliance if needed

• If an operator believes that an alternative inspection technique, different SB revision, or alternative repair method would be appropriate, the supplied AD extract provides no explicit alternative method of compliance process. Operators should therefore consult the full AD and CASA guidance about seeking approvals or alternative methods, and coordinate any required FAA Wichita ACO approvals for certain repair methods as specified by the AD.

10. Coordinate cross-authority approvals and record evidence

• Where the AD requires FAA Wichita ACO approval for a repair method (Requirement 3), submit the necessary documentation and obtain written approval. Retain the FAA approval documentation and include it in maintenance records as part of demonstrating AD compliance.

Summary of immediate practical steps: obtain SB 35/36-51-3 and SB 35/36-51-4 Rev 1/Rev 2; confirm aircraft applicability; complete the detailed probe and general visual inspections in accordance with SB 35/36-51-3; measure resistance and act per the specified thresholds; where required, perform repairs/modifications per SB 35/36-51-4 Rev 1 or Rev 2; if crack openings exceed 0.030-inch, obtain FAA Manager, Wichita ACO approval for the repair method and perform the terminating action specified in Requirement 4, the text of which must be located in the full AD.

Operators should not rely solely on the extract supplied here for compliance because the extract omits the compliance timing and Requirement 4 text; the full AD document and the cited Bombardier SBs must be used to determine exact timing, procedures and the identity of the terminating action.