AD/CRESCO/9 - MLG Lower Torque Links

This AD is built on a small set of technical and regulatory concepts that determine both the required actions and how those actions are to be performed.

Applicability and scope: The AD applies to "Model 08-600 aircraft on restricted category agricultural operations, fitted with main landing gear (MLG) lower pivot torque link bolts part number (P/N) NAS 1307-78D" (Applicability). That combination defines which aircraft and operations are in scope.

Two-tiered inspection regime: There are two complementary inspection obligations. The first is an inspection of the MLG torque link assemblies for wear, carried out per specified chapters and pages of the PAC Cresco 08-600 Maintenance Manual (Requirement 1). The second is removal and non-destructive testing (NDT) of the MLG lower pivot torque link bolts using magnetic particle inspection equivalent to ASTM E-1444 (Requirement 2.a). The AD requires replacement or rework of worn parts and replacement of cracked bolts before further flight.

Integration with the aircraft maintenance manual and engineering drawings: The AD does not stand alone; it explicitly incorporates by reference specific chapters and pages of the PAC Cresco 08-600 Maintenance Manual, and PAC Drawing 08-03179 for rework dimensions (Note 3). It also references manufacturer engineering changes (MOD PAC/CR/0300, MOD PAC/CR/0435) as acceptable corrective paths.

Technical standards and inspection method equivalence: The AD mandates an "approved direct or indirect magnetic particle inspection method that is equivalent to ASTM International Standard No. E-1444" to detect surface or slightly subsurface discontinuities in ferromagnetic material (Requirement 2.a; Note 1). The AD therefore relies on an external consensus standard for test performance and equivalence rather than prescribing a single proprietary test procedure.

Immediate operational limits linked to corrective action: The AD uses the phrase "before further flight" repeatedly for replacement/rework of worn parts and replacement of cracked bolts (Requirement 1; Requirement 2.a). This establishes that discovery of certain defects imposes an immediate prohibition on further flight until the corrective action is completed.

Compliance timing and recurrent inspections: There is a time-in-service based compliance schedule: initial action within 150 hours time in service after 15 February 2007 or before bolts exceed 300 hours time in service, whichever is later, and thereafter inspections not to exceed 300 hours time in service between inspections (Compliance). The AD therefore sets both a retroactive window and a recurring frequency based solely on flight hours.

Interplay with alternate parts and rework: The AD provides alternative engineering solutions: MOD PAC/CR/0300 is noted as installation of alternate lower torque link bolts and torque plate assemblies; MOD PAC/CR/0435 introduces replaceable bushes per PAC Drawing 08-03179, and lower torque link assemblies P/N 08-40091-1 can be reworked and re-identified as P/N 08-40031-4 if wear does not exceed rework dimensions in that drawing (Notes 2 and 3). Those paths are presented as remediation options where allowable within the engineering limits.

Cross-reference to other authorities: The AD notes that NZ CAA AD DCA/CRESCO/9 refers (Note 4), indicating coordination or parallel action by another civil aviation authority. The AD is signed by a CASA delegate, indicating the issuing authority.

Units and measurement: The AD prescribes torque values in inch-pounds (180 to 210 inch-pounds), and inspection intervals in hours time in service. The use of imperial torque units is explicit.

Taken together, these concepts produce a set of mechanically prescriptive tasks tied to the PAC maintenance manual and engineering drawings, coupled with a defined inspection cadence and immediate flight restrictions when certain defects are found.

The AD singles out a narrowly defined set of stakeholders directly affected by its requirements. Operators: Aircraft operators who fly Pacific Aerospace Corporation Cresco model 08-600 aircraft "on restricted category agricultural operations" and whose MLG lower pivot torque link bolts are P/N NAS 1307-78D are the primary group required to comply (Applicability). For those operators, the AD prescribes initial and recurring inspections, and mandates corrective action "before further flight" where wear or cracking is observed.

Maintenance organisations and certificated engineers: The AD requires inspections "in accordance with" specified chapters of the PAC Cresco 08-600 Maintenance Manual (Requirement 1 and 2.b). That binds the practical execution of the inspections and rework to those who have access to, and authority to carry out work per, the PAC manual, so persons licensed or authorised to maintain such aircraft will be engaged. The AD also requires the use of an "approved direct or indirect magnetic particle inspection method that is equivalent to ASTM ... E-1444" (Requirement 2.a and Note 1). That implicates non-destructive testing (NDT) providers with appropriate equipment and accreditation or approval to perform MPI to that standard.

Parts and engineering suppliers: The AD references specific part numbers and modifications: P/N NAS 1307-78D (fitted bolts), lower torque link assemblies P/N 08-40091-1 and re-identified P/N 08-40031-4 (for reworked assemblies), MOD PAC/CR/0300 (alternate bolts and torque plate assemblies), and MOD PAC/CR/0435 (replaceable bushes per PAC Drawing 08-03179) (Requirement 1; Notes 2-3). Suppliers of replacement bolts, torque link assemblies, torque plates or bushes and the engineering organisations that perform MODs will therefore be in the supply chain affected by demand for replacement parts or rework workscopes.

Regulatory authorities: The document is signed by "David Villiers, Delegate of the Civil Aviation Safety Authority" (signature block). That indicates CASA as the issuing body within the provided text. The AD also refers to NZ CAA AD DCA/CRESCO/9 (Note 4), which implicates the New Zealand Civil Aviation Authority as a related regulator. The presence of that cross-reference means that operators or maintainers who operate in or across those jurisdictions may need to coordinate with both authority requirements.

Aircraft owners: Owners of the affected aircraft bear direct financial and operational consequences: the AD requires inspections and possibly replacement or rework "before further flight." That creates potential downtime, maintenance costs and parts expense.

Flight operations and scheduling: Because compliance is tied to hours time in service and requires action before further flight where defects are found, operators who plan continuous agricultural flying will need to schedule inspections to fit within the compliance window (initial: within 150 hours after 15 February 2007 or before bolts exceed 300 hours TS; recurring: intervals not to exceed 300 hours TS) and allow for potential grounding while corrective actions are completed.

Insurers and lessors: Although not mentioned in the AD text, insurers and lessors will be indirectly affected in practice by mandatory airworthiness action that limits flyability until compliance is achieved. The AD itself does not mention insurance or lease obligations; the source text does not impose or describe those relationships.

In short, the AD affects operators of the specified Cresco aircraft in restrictedcategory agricultural service, their maintenance providers and part suppliers, and the issuing regulator(s), with owners bearing costs and scheduling impacts. The AD’s applicability statement is the definitive gate for determining who is captured by the directive.

The AD delineates specific duties for affected operators and maintenance personnel and embeds immediate "before further flight" conditions. The source text does not set out rights in the sense of appeal or challenge within the instrument; it sets mandatory technical duties.

Primary duties

• Inspect MLG torque link assemblies for wear as specified: The operator must "Inspect the MLG torque link assemblies for wear in accordance with the maintenance schedule in Chapter 05-10-00 page 615, and the MLG wear limits in Chapter 32-10-00 page 601, of Pacific Aerospace Corporation (PAC) Cresco08-600 Maintenance Manual" (Requirement 1). If wear is found, worn parts must be replaced or reworked "before further flight." This duty ties inspection practice explicitly to the manufacturer's manual chapters and pages.

• Replace or incorporate modification for specific part numbers: Where the lower torque link assembly is P/N 08-40091-1 and is found worn, the operator must "Replace a worn lower torque link assembly P/N 08-40091-1, or incorporate MOD PAC/CR/0435, before further flight" (Requirement 1). That provides two alternative corrective actions but requires completion prior to flight.

• Remove and NDT inspect lower pivot torque link bolts: The operator must "Remove the MLG lower pivot torque link bolt in accordance with Chapter 32 of the PAC Cresco 08-600 Maintenance Manual" and then "Inspect the lower pivot torque link bolts using an approved direct or indirect magnetic particle inspection method that is equivalent to ASTM International Standard No. E-1444" (Requirement 2.a). If the bolts are cracked, they must be replaced "before further flight."

• Re-assemble, lubricate and torque to specified values: After inspection and any replacement or rework, the lower torque link assembly must be "Re-assemble and lubricate the lower torque link assembly in accordance with Chapters 32 and 12 of PAC Cresco 08-600 Maintenance Manual" and the bolts must be torqued to "180 to 210 inch-pounds" (Requirement 2.b).

• Observe inspection cadence: Initial compliance requires action "Within 150 hours time in service after 15 February 2007 or before MLG lower pivot torque link bolts exceed 300 hours time in service, whichever occurs later." Thereafter inspections are required "at intervals not to exceed 300 hours time in service" (Compliance).

Rights and scope limitations within the AD text

• The AD provides specified corrective options but does not indicate procedural rights such as appeal or deferral. It states remedial alternatives (for example, replace assembly P/N 08-40091-1 or incorporate MOD PAC/CR/0435) but does not grant a discretionary exception in the text provided.

• The AD prescribes the inspection method but allows equivalence by reference: it requires an "approved direct or indirect magnetic particle inspection method that is equivalent to ASTM ... E-1444" (Requirement 2.a; Note 1). That creates a duty to use an approved method but allows the method to be deemed acceptable if equivalent to the cited standard; the AD does not include the approval mechanism or who grants equivalence in its text.

• For rework, the AD permits re-identification of assemblies: "Lower torque link assemblies P/N 08-40091-1 can be reworked and re-identified as P/N 08-40031-4 if the wear damage does not exceed the rework dimensions in PAC Drawing 08-03179" (Note 3). That creates a pathway to retain parts by rework subject to drawing limits.

Constraints and immediate operational prohibition

• The repeated term "before further flight" sets an immediate operational constraint: where wear exceeds the manual limits or bolts are cracked, flight is not permitted until the prescribed corrective action is done. The AD uses that phrase for both replacement/rework of worn parts and replacement of cracked bolts (Requirement 1; Requirement 2.a).

• The AD does not set out who may perform the inspections or replacement explicitly in the text supplied. It does, however, refer to the PAC maintenance manual chapters as the procedural authority for those tasks, which implies use of the manual's approved maintenance practices.

Documentation and standards reference duties

• The AD requires reference to specific manufacturer documentation (PAC Cresco 08-600 Maintenance Manual chapters and PAC Drawing 08-03179) and a specified industry standard (ASTM E-1444). The duty is therefore to follow, and be able to demonstrate compliance with, those referenced technical documents.

In sum, the AD imposes specific maintenance, inspection, replacement, rework and torqueing duties, prescribes timing for initial and recurring inspections, and ties those duties to manufacturer manuals, engineering drawings and an external NDT standard. The AD text does not set out procedural rights such as challenge, variance or appeal.

The AD text provided does not set out penalties, fines or explicit enforcement procedures. It prescribes mandatory maintenance and inspection actions and includes operational constraints expressed as "before further flight" requirements, but within the text given there are no clauses that specify civil or criminal penalties, administrative sanctions, or the enforcement mechanisms that the issuing authority might use to secure compliance.

What the AD does state that has enforcement implications

• Mandatory action and effective date: The AD "becomes effective on 15 February 2007" (Compliance) and prescribes mandatory actions to be completed within defined timeframes. The language used in an AD context in this document is prescriptive and unqualified; for example, replacement and rework are mandated "before further flight" in certain circumstances, implying that continuing to operate an aircraft with the defects described would be contrary to the directive.

• Operational prohibition implicit in "before further flight": The phrase "before further flight" establishes a practical ground rule that defects identified in the inspections must be corrected prior to continuing flight operations. The AD thereby creates an operational constraint that must be observed to continue legal, airworthy operation under typical aviation regulatory frameworks. The AD text itself does not elaborate the consequences of failing to comply with that constraint.

• Reference to other authority: The AD is signed by a delegate of the Civil Aviation Safety Authority (CASA) and references NZ CAA AD DCA/CRESCO/9 (Note 4). The signature block indicates the issuing authority, which in practice would have regulatory tools to enforce airworthiness directives, though the AD text as supplied does not describe those tools.

What is not in the AD text

• No penalties, no enforcement process: The AD does not contain any penalty schedule or describe inspection, audit or enforcement procedures such as notices, suspensions, fines or prosecutions. It does not explain how an operator might seek a temporary exemption, nor does it specify reporting or certification requirements beyond the maintenance actions themselves.

• No delegated approval details: The AD mandates the use of an "approved" MPI method equivalent to ASTM E-1444 but does not state who approves specific NDT methods or providers nor the process for obtaining that approval.

Practical implication for operators and maintainers

• While the AD omits explicit penalty provisions, the mandatory nature of the requirements and the "before further flight" phrasing mean that operators who do not comply will be operating aircraft contrary to the requirements of this AD. The text supplied does not state the enforcement route, so to understand enforcement and potential sanctions an operator must consult the issuing authority's regulatory framework and enforcement policies outside of this AD text.

In short, the AD sets mandatory technical requirements and effective dates but does not itself include detailed enforcement or penalties within the provided text. Determination of penalties or enforcement action would rest on the broader regulatory law and administrative practices of the authority outside the AD text.

The AD binds its technical requirements to specific manufacturer documents, an industry inspection standard and references a corresponding foreign authority's AD. Within the text supplied, interaction with other laws is implicit through these cross-references, but the AD does not reproduce or restate any external legal instruments or statutory provisions.

Incorporation by reference of manufacturer material and standards

• The AD requires that inspections and corrective actions be performed "in accordance with" specific parts of the Pacific Aerospace Corporation Cresco 08-600 Maintenance Manual (Chapters 05-10-00 page 615, 32-10-00 page 601, and Chapters 32 and 12) (Requirement 1; Requirement 2.b). That makes the manufacturer-maintenance manual practically operative for the AD’s purposes. The AD thereby interacts with and depends on the content of that manual for procedural details; compliance with the AD requires compliance with those manual provisions.

• The AD requires the use of an "approved direct or indirect magnetic particle inspection method that is equivalent to ASTM International Standard No. E-1444" for bolt inspection (Requirement 2.a; Note 1). That incorporates a consensus technical standard as the benchmark for inspection performance. Operators must therefore ensure their inspection method is equivalent to ASTM E-1444 and approved, which ties the AD to that external standard.

References to modifications and engineering drawings

• The AD references unit-specific modifications and drawings: MOD PAC/CR/0300 (installation of alternate lower torque link bolts and torque plate assemblies), MOD PAC/CR/0435 (introduces replaceable bushes in accordance with PAC Drawing 08-03179), and PAC Drawing 08-03179 (rework dimensions) (Notes 2-3). These manufacturer engineering modifications are treated as acceptable corrective measures within the AD. The AD therefore interacts with the manufacturer's modification regime and drawings as engineering controls accepted by the authority.

Cross-jurisdictional coordination

• The AD notes "NZ CAA AD DCA/CRESCO/9 refers" (Note 4). That indicates a parallel or related action by the New Zealand Civil Aviation Authority. The AD therefore interacts de facto with the regulatory actions of another national aviation authority. The provided text does not specify whether compliance with the NZ CAA AD satisfies this AD or vice versa, only that the NZ CAA AD is relevant.

Missing elements about statutory interactions

• The AD text does not identify the specific enabling statute or legislative provision under which it is issued. It does identify the issuing authority by signature, but it does not state the statutory mechanics (for example, provisions of an Aviation Act) that confer legal force on the AD text. Those details are not part of the supplied text.

• The AD does not state whether compliance with the AD alters certification, registration, operating limitations, or insurance obligations directly in statutory terms. It also does not specify how conflicts are to be resolved if manufacturer guidance differs from the AD, or how to obtain an approved alternative method or deviation under law.

Operational interaction with maintenance regulation

• By linking to the maintenance manual and the ASTM standard, the AD interacts operationally with maintenance regulations and NDT approval processes. Operators will need to ensure that the persons performing the inspections and rework have the necessary authorisations and approvals under the applicable maintenance regulation, though the AD does not itself spell out those authorisations.

In summary, the AD interacts with other technical regulatory instruments by incorporating manufacturer manuals, engineering modifications and an ASTM inspection standard, and it cross-references a New Zealand AD. The AD text does not itself recite the enabling statute, enforcement provisions, or procedures for seeking alternative methods; those legal interactions must be sought in the issuing authority's broader regulatory framework.

The text provided contains a single issuance and does not include a multi-version amendment log within the document. From the supplied material the following items serve as the contemporaneous record of issuance and identifier information.

• AD identifier and date: The directive is designated AD/CRESCO/9 and carries the notation "2/2007" in the header. That numbering is reproduced several times in the document header rows.

• Effective date: The AD states that it "becomes effective on 15 February 2007" (Compliance). It is also dated 5 January 2007 in the signature block, where "David Villiers, Delegate of the Civil Aviation Safety Authority" is shown.

• No later amendments shown: The AD text supplied includes no material that amends, supersedes, or withdraws another AD. There is no explicit record within the supplied text of prior versions, amendments, cancellations or replacements. The document has no separate amendment history section; therefore, the single effective issuance is the only action recorded in the supplied text.

• References to other documents and previous ADs: The AD includes cross-references that may indicate parallel or predecessor actions,specifically, the note "NZ CAA AD DCA/CRESCO/9 refers" (Note 4). That suggests that a New Zealand AD covering similar issues exists, but the AD text does not state whether the NZ AD pre-dated this AD or whether the present AD is an adoption or variation. The AD also references manufacturer modifications and drawings (MOD PAC/CR/0300, MOD PAC/CR/0435, PAC Drawing 08-03179) which may themselves be the product of earlier engineering changes, but the AD text does not provide dates for those MODs or drawings or describe any update history.

• Document signatures and issuance trace: The signature block shows the AD was signed on 5 January 2007, which gives an issuance date earlier than the effective date. No subsequent amendment entries or revision dates appear in the supplied text.

Practical import

• Legal users seeking a complete amendment history will need to consult the issuing authority's AD repository or the PAC serviceability documentation to ascertain whether later ADs amended or cancelled this directive, or whether later OEM revisions change the referenced manuals or MODs. The AD as supplied contains only the initial issuance data: designation AD/CRESCO/9, notation 2/2007, signature dated 5 January 2007, and effective date 15 February 2007.

The AD text supplied contains no information about litigation or legal challenges. It does not cite any court decisions, enforcement actions, appeals, or administrative reviews arising from this directive. The document does not present any record of disputes, judicial interpretation, settlements, or case law related to the AD.

What the AD supplies and what it does not

• No case citations: There are no references to court decisions or legal proceedings in the body of the AD, notes or signature block.

• No administrative appeals record: The AD does not indicate whether there were requests for exemptions, alternative methods of compliance (AMOCs), or appeals against the directive, nor any decisions on such matters.

• No enforcement or litigation narrative: The AD does not recount any enforcement steps taken against operators for non-compliance nor does it state whether compliance monitoring led to legal proceedings.

Practical consequences

• Absence of litigation history in the AD text does not imply that no litigation or disputes occurred; the supplied AD simply does not record such matters. Practitioners needing to know whether this AD was contested, litigated, or otherwise resulted in legal proceedings will need to search external records such as regulator enforcement logs, administrative appeal tribunal files, or court dockets in the relevant jurisdictions.

• Operators wanting to understand precedent or contested points should consult the issuing authority or legal databases for any administrative reviews, decisions on AMOCs, or other litigation that might interpret or constrain the AD’s requirements. None of that material is present in the AD as provided.

The AD’s language and technical cross-references create specific practical pitfalls and operational traps that an operator or maintainer should note. These are grounded in the text supplied and flow from its prescriptive nature, referenced documents, units, and timing.

Applicability can be narrowly framed and must be interpreted by part number and operation type: The AD applies only to "Model 08-600 aircraft on restricted category agricultural operations, fitted with MLG lower pivot torque link bolts P/N NAS 1307-78D" (Applicability). Aircraft that are 08-600 models but not in restricted category agricultural operations, or that have different bolt P/Ns fitted, are outside the AD’s stated scope. Failure to check the bolt P/N could lead to unnecessary work or to mistakenly assuming applicability for non-covered aircraft.

Timing window complexity: The initial compliance requirement is phrased as "Within 150 hours time in service after 15 February 2007 or before MLG lower pivot torque link bolts exceed 300 hours time in service, whichever occurs later" (Compliance). That creates a two-variable trigger: both calendar/clock time relative to the effective date and the individual bolt's hours in service. Operators must track each bolt’s accumulated hours time in service to determine whether to inspect earlier than the 150-hour window. Misreading "whichever occurs later" could result in delayed inspection beyond the bolt life limit.

Recurring interval unit: Inspections are required "at intervals not to exceed 300 hours time in service" (Compliance). The interval is measured in hours time in service, not calendar months, cycles, landings or flights. Organisations that track only calendar-based maintenance may overlook the hours TS basis.

Imperial torque units: The reassembly torque is specified "180 to 210 inch-pounds" (Requirement 2.b). Operators that use metric tools must convert accurately. Using the wrong units or misinterpreting the specification could yield under- or over-torqued bolts, which may cause further failures or be non-compliant with the AD.

Specified NDT equivalence and approval: The AD requires an "approved direct or indirect magnetic particle inspection method that is equivalent to ASTM ... E-1444" (Requirement 2.a; Note 1). The AD does not identify the approving authority or process for establishing that equivalence. Operators must secure an "approved" MPI method or provider; uncertainty about who grants approval or what documentation suffices may delay inspections.

Reference to manufacturer documentation and drawings: The AD instructs compliance "in accordance with" particular chapters and pages of the PAC Cresco 08-600 Maintenance Manual, and references PAC Drawing 08-03179 for rework dimensions and MOD PAC/CR/0300 and MOD PAC/CR/0435 as remedial options (Requirement 1; Notes 2-3). Failure to use the exact cited pages or drawing dimensions risks non-compliance. Access to those specific manual pages and drawings is therefore necessary.

Re-identification of reworked parts: The AD permits reworking P/N 08-40091-1 and re-identifying it as P/N 08-40031-4 "if the wear damage does not exceed the rework dimensions in PAC Drawing 08-03179" (Note 3). Absent careful measurement against the drawing, a rework could exceed allowable limits and produce an improperly re-identified part.

Before further flight constraint: Both wear beyond manual limits and cracked bolts trigger a "before further flight" corrective requirement (Requirement 1; Requirement 2.a). Operators must not attempt to fly with those defects. Misunderstanding the immediacy of this prohibition could result in continued operation contrary to the directive.

Cross-jurisdictional reference: The AD notes "NZ CAA AD DCA/CRESCO/9 refers" (Note 4). Operators operating across jurisdictions should check the NZ AD for differences or additional obligations. Assuming the NZ AD is identical without checking may be a mistake.

No enforcement details in text: The AD does not specify enforcement mechanisms or penalties; this absence means operators cannot rely on the AD text alone to determine consequences of non-compliance. They must consult the regulator for enforcement policies. That administrative gap can complicate risk assessment.

Potential parts availability and downtime: The AD requires replacement of cracked bolts and potentially replacement of assemblies P/N 08-40091-1 or incorporation of MOD PAC/CR/0435 before further flight. If parts or MOD kit availability is constrained, aircraft may be grounded. The AD does not provide for temporary extensions or interim mitigation measures within the text supplied.

Summary of practical "gotchas": confirm exact applicability by checking P/N and operation type; track individual bolt hours time in service; use hour-based recurring inspections; obtain an approved MPI method equivalent to ASTM E-1444; secure the specified manual pages and drawings; measure rework to the drawing limits before re-identifying parts; torque to the specified 180-210 inch-pounds using correct units; treat "before further flight" as an immediate no-fly condition until corrected; and consult the regulator for enforcement expectations and for any cross-jurisdictional implications with the NZ CAA AD.

The AD prescribes a concrete, bounded set of actions. The following checklist turns the AD’s text into operational steps that maintainers and operators can follow while keeping to the wording and references in the AD.

1. Confirm applicability

   • Verify the aircraft is a Pacific Aerospace Corporation Cresco model 08-600.
   • Confirm the aircraft is operated in "restricted category agricultural operations."
   • Confirm the installed MLG lower pivot torque link bolts are P/N NAS 1307-78D. If any of these three conditions are not met, the AD as written does not apply to that aircraft (Applicability).

2. Establish time-in-service records for the bolts

   • Determine each bolt’s accumulated hours time in service. This is necessary to apply the compliance timing: initial inspection is required "Within 150 hours time in service after 15 February 2007 or before MLG lower pivot torque link bolts exceed 300 hours time in service, whichever occurs later" (Compliance).
   • Plan inspections so that no bolt exceeds 300 hours time in service before the initial inspection has been completed.

3. Schedule and perform initial torque link assembly wear inspection

   • Inspect the MLG torque link assemblies for wear "in accordance with the maintenance schedule in Chapter 05-10-00 page 615, and the MLG wear limits in Chapter 32-10-00 page 601, of PAC Cresco08-600 Maintenance Manual" (Requirement 1).
   • Compare findings against the manual’s wear limits. If wear exceeds the manual limits, proceed to corrective actions; otherwise record the inspection outcome and schedule the next inspection for not more than 300 hours time in service later.

4. Corrective actions for worn lower torque link assemblies

   • If wear is found on a lower torque link assembly P/N 08-40091-1, either replace that assembly or incorporate MOD PAC/CR/0435 before further flight (Requirement 1).
   • If rework is an option, consult PAC Drawing 08-03179 to ensure wear dimensions are within allowable rework limits and rework and re-identify as P/N 08-40031-4 only if within those dimensions (Note 3).

5. Remove and inspect lower pivot torque link bolts

   • Remove the MLG lower pivot torque link bolts "in accordance with Chapter 32 of the PAC Cresco 08-600 Maintenance Manual" (Requirement 2).
   • Inspect the removed bolts using an "approved direct or indirect magnetic particle inspection method that is equivalent to ASTM International Standard No. E-1444" (Requirement 2.a; Note 1).
   • Ensure the NDT provider is able to certify equivalence to ASTM E-1444 or is otherwise "approved" as required by the AD text.

6. Replace cracked bolts

   • If magnetic particle inspection reveals cracking under the bolt head or elsewhere, replace the bolts "before further flight" (Requirement 2.a).

7. Reassembly, lubrication and torqueing

   • After inspection, replacement or rework, re-assemble and lubricate the lower torque link assembly "in accordance with Chapters 32 and 12 of PAC Cresco 08-600 Maintenance Manual" (Requirement 2.b).
   • Torque the MLG lower pivot torque link bolts to 180-210 inch-pounds (Requirement 2.b). Ensure correct torque tools and, if necessary, correct conversion from metric units.

8. Consider MOD PAC/CR/0300

   • MOD PAC/CR/0300 is an alternative corrective path that installs alternate lower torque link bolts and torque plate assemblies (Note 2). If considering MOD PAC/CR/0300, consult the MOD documentation and PAC manual guidance to ensure proper installation and airworthiness acceptance.

9. Document the work and schedule recurring inspections

   • Record the inspection findings, any rework or replacement performed, and the torqueing procedure and values used. While the AD text supplied does not specify recordkeeping requirements, good practice is to retain entries consistent with maintenance manual and regulatory requirements.
   • Schedule subsequent inspections at intervals "not to exceed 300 hours time in service" (Compliance).

10. Coordinate with regulator and cross-reference documents

• Consult the PAC Cresco 08-600 Maintenance Manual Chapters and PAC Drawing 08-03179 as cited in the AD for procedural details and rework dimensions.
• Ensure the chosen magnetic particle inspection method is approved and equivalent to ASTM E-1444.
• Review NZ CAA AD DCA/CRESCO/9 as referenced (Note 4) to identify any additional or divergent obligations if operating across jurisdictions.
• If uncertain about approval for an MPI method, applicability, or how to treat reworked parts, contact the issuing authority as the AD does not set out approval or enforcement procedures in the text provided.

Operational cautions and resource steps

• Availability of parts and MOD kits: Anticipate potential lead times for replacement bolts, torque plate assemblies or MOD kits and plan maintenance scheduling to avoid excessive downtime.

• Skilled personnel and NDT provision: Ensure that maintenance personnel and NDT providers are capable and authorised to perform the referenced procedures and that NDT reports document equivalence to ASTM E-1444 where required.

• Torque calibration: Use calibrated torque tools and ensure torque measurements are consistent with the specified 180-210 inch-pound range.

• Scope control: Apply the AD to the specific aircraft/operation/part-number combination identified; do not extrapolate the AD’s requirements to other models or configurations without explicit textual support.

Following these steps aligns maintenance practice directly with the AD’s requirements as stated in the supplied text and reduces the risk of non-compliance or inadvertent operation contrary to the directive.