AD/PA-31/93 Amdt 2 - Main Landing Gear Inboard Door Hinge

The document operates as an airworthiness prescriptive instrument rather than as a general statute. The central concepts are applicability, specific technical requirement, compliance timing, approved parts, and amendment authority.

Applicability is defined with serial-number precision. The AD lists explicit serial-number ranges for each model variant (for example, PA-31: 31-2 through 31-900 and 31-7300901 through 31-8312019; PA-31-350: 31-5001 through 31-5004 and 31-7305005 through 31-8553002; and so on). These serial-number ranges determine whether an aircraft falls within the AD’s scope. The AD does not create a model-wide obligation irrespective of serial number; it applies to the listed serials only.

The technical requirement is narrow and mechanical. Both Requirements 1 and 2 specify the same two-step action: (a) inspect all hinges and hinge attachment angles in the MLG inboard door hinge assembly; and (b) replace any cracked assembly with Piper part number 47529-32 or an FAA- or CASA-approved equivalent. The reference to "the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980" makes that service bulletin an operational component of compliance: the AD requires actions performed in accordance with the SB’s instructions. The AD distinguishes assemblies by part number and material: the 47529-32 assembly (and its approved equivalents) is treated separately from aluminium or other non-steel assemblies, which are subject to more frequent inspections.

Compliance timing is explicit and asymmetric. For assemblies that are Piper part 47529-32 (or approved equivalents), the initial inspection is either upon accumulation of 2,000 hours TIS on the hinge assembly or within the next 100 hours TIS after 19 April 2001, whichever is later; thereafter inspections are every 2,000 hours TIS. For aluminium or other non-steel assemblies the inspection timing is the next inspection required by the previous AD or within the next 100 hours TIS after 19 April 2001 whichever occurs first, then every 100 hours TIS. Where cracked assemblies are discovered they must be replaced before further flight. The AD thereby imposes both periodic inspection intervals and an immediate grounding requirement until replacement where cracking is found.

Approved parts language is a key lever. The AD requires replacement with Piper PN 47529-32 or "FAA or CASA-approved equivalent part number". Amendment 2 explicitly expands permissible replacements to include CASA-approved parts as alternatives to Piper and FAA-approved parts. That ties procurement and installation decisions to the approval status of parts and potentially to CASA’s approval process.

Authority and formality are also explicit. The AD is issued under subregulation 39.1(1) of CAR 1998, is signed by the CASA delegate, and is notified in the Commonwealth Gazette. It revokes the immediately prior amendment (Amdt 1), so compliance must follow this amendment’s instructions rather than Amendment 1. The Background ties the AD to operational risk (instances of MLG inboard door hinge failure) and to prior FAA action (FAA AD 80-26-05) that motivated Amendment 1.

Primary affected parties are aircraft operators and owners of the listed Piper PA-31 series aeroplanes within the specified serial-number ranges, maintenance organisations and certifying engineers that perform inspections and replacements, parts suppliers and manufacturers of the MLG inboard door hinge assembly (particularly suppliers of Piper part number 47529-32 and any CASA- or FAA-approved equivalents), and the Civil Aviation Safety Authority as regulator and approver.

Operators: The AD places inspection and replacement obligations directly on aircraft operators or their maintenance providers because they must ensure the MLG inboard door hinge assemblies are inspected and cracked assemblies replaced, in accordance with the Compliance timing. The requirement that replacement be accomplished "before further flight after the inspection" when cracking is found imposes immediate operational constraints: aircraft with cracked hinge assemblies cannot fly until the specified replacement is installed.

Maintenance organisations and certifying personnel: The AD requires inspections "in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980." That binds maintenance actions to the technical instructions of that Service Bulletin; organisations performing the inspection must have access to and follow the SB instructions. Certifying engineers will need to record compliance and ensure installation of the specified Piper part number or an approved equivalent. For aluminium or non-steel assemblies, the more frequent 100-hour inspection interval increases workload for maintenance providers on affected aircraft.

Parts suppliers and manufacturers: The AD creates demand for Piper PN 47529-32 assemblies and for FAA- or CASA-approved equivalents. Amendment 2’s explicit inclusion of CASA-approved parts as alternatives expands the set of acceptable replacement parts, which may affect procurement options, domestic supplier participation, and the approval process for alternative assemblies.

Regulator: CASA is the decision-maker on approval of equivalent parts, and the AD itself is issued under CASA’s statutory subregulation authority (CAR 1998 subreg 39.1(1)). The AD is signed by the CASA delegate (David Alan Villiers) and was notified in the Commonwealth Gazette. CASA also oversees enforcement under the regulatory framework, and its approvals determine which replacement parts are permissible.

Other stakeholders: Operators’ insurers and lessors of the affected aeroplanes will be affected in practical terms because mandatory inspections, potential grounding for replacements, and changes in maintenance regimes can influence operational availability, premiums, and contractual obligations. The AD does not mention insurers or lessors by name but the operational obligations will have downstream contractual and commercial effects.

Geographic scope: The AD is a CASA instrument and is notified in the Commonwealth of Australia Gazette; the Background explicitly references "local aircraft" incidents. The AD also refers to FAA-approved parts and to the FAA AD that previously prompted Amendment 1; this signals cross-jurisdictional interaction where FAA action informed CASA’s response.

Duties

• Inspect hinges and hinge attachment angles: Both Requirement 1 and Requirement 2 mandate inspection "of all hinges and hinge attachment angles in the MLG inboard door hinge assembly" and require that the inspections be accomplished "in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980." This creates a duty to follow the SB’s technical procedure (Requirement 1(a) and Requirement 2(a)).

• Replace cracked assemblies with specified parts: Both Requirements mandate replacement "of any cracked MLG inboard door hinge assembly with a Piper part number 47529-32 assembly (or FAA or CASA-approved equivalent part number)" (Requirement 1(b) and Requirement 2(b)). Replacement is not optional when cracking is found; it is a prescribed corrective step.

• Timing obligations: The Compliance section sets enforceable timing obligations. For Piper 47529-32 assemblies (or approved equivalents), operators must inspect upon accumulating 2,000 hours TIS on the assembly or within the next 100 hours TIS after 19 April 2001, whichever occurs later, and subsequently at intervals not exceeding 2,000 hours TIS (Compliance 1). For aluminium or other non-steel assemblies that are not Piper 47529-32 (or equivalents), operators must inspect at the next inspection required by the previous issue of this Directive or within the next 100 hours TIS after 19 April 2001, whichever occurs first, and thereafter at intervals not exceeding 100 hours TIS (Compliance 2). Where cracked assemblies are found replacement must be "before further flight after the inspection."

• Adherence to Service Bulletin: The AD explicitly ties the inspection and replacement actions to the instructions in Piper Service Bulletin No. 682, dated 24 July 1980, so the duty is not just to inspect generally but to perform the inspection as specified in that document.

Rights

• Use of approved equivalents: Amendment 2 expands allowed replacement parts to include "CASA-approved parts as an alternative to the Piper and FAA-approved parts." This is a right or option for operators: provided they obtain CASA approval or use an FAA-approved equivalent, they may install the approved substitute rather than strictly only the Piper part number.

• Clarity on required action: The AD sets discrete, verifiable actions (inspect, replace cracked assemblies) and discrete timing intervals, which provides operators with a deterministic compliance pathway rather than discretionary obligations.

Who decides

• CASA delegate and CASA approvals: The AD is issued by a CASA delegate (David Alan Villiers) and refers to CASA-approved equivalents as permissible replacements. This means CASA has decision-making authority concerning what constitutes an acceptable alternative part.

What must be recorded or done post-action

• Replacement before further flight: Where a cracked assembly is found, replacement is required before further flight after the inspection. This creates a de facto grounding until corrective action is completed and documented.

• Compliance with previous directive: For the aluminium/non-steel assemblies the AD refers back to the "next inspection required by the previous issue of this Directive", signalling that operators must track prior AD compliance schedules and coordinate them with this Amendment.

What the AD does not create

• The AD does not set out a penalty schedule, does not specify how CASA approves equivalents, and does not authorise specific repairs other than replacement with the specified part or approved equivalent. It also does not set out who bears the cost in explicit terms; those obligations follow from the operational duty to perform inspections and replacements.

The AD does not itself enumerate specific penalties or civil or criminal sanctions for non‑compliance within the text supplied. The AD is issued "under subregulation 39.1 (1) of CAR 1998," which establishes the statutory basis for CASA to issue airworthiness directives; enforcement and penalties arising from non-compliance would therefore be matters governed by CAR 1998 and other relevant aviation enforcement provisions, not by the text of this AD. The AD is signed by the CASA delegate and was notified in the Commonwealth of Australia Gazette, which provides formal promulgation.

Practical enforcement mechanisms implicit in the AD

• Regulatory authority: Because the AD is an instrument issued under CAR 1998, CASA has regulatory authority to require compliance and to take enforcement action under the broader Civil Aviation regulatory regime. The AD itself sets mandatory maintenance and operational actions,inspections, replacement before further flight if cracking is found, and adherence to specified intervals,that CASA expects operators to follow. Non-compliance may therefore expose operators to enforcement measures available to CASA under CAR 1998; the AD text does not specify which measures or their magnitude.

• Operational control: The AD imposes an immediate operational consequence where cracks are found: replacement must be carried out "before further flight." This creates a direct operational enforcement lever,aircraft found with a cracked assembly cannot lawfully continue to fly until the mandated replacement is completed and recorded.

• Approval gatekeeping: The AD requires replacement parts to be Piper part number 47529-32 "or FAA or CASA-approved equivalent part number." CASA’s approval authority over equivalents gives the regulator a gatekeeping role over what replacements are permitted. If an operator uses an unapproved part, that would be non-compliance with the AD.

Notification and formal effectiveness

• The AD was notified in the Commonwealth of Australia Gazette (notification date given as 21 March 2001) and became effective on 19 April 2001. Publication and Gazette notification are formal steps that underpin enforceability; the AD’s effective date establishes the timeline for compliance obligations as set out in the Compliance section.

What the AD does not state about enforcement

• The AD text does not specify inspection documentation requirements, fines or penalties, suspension or revocation procedures, or administrative processes for CASA enforcement. It does not specify how CASA will verify compliance or whether periodic audits will be conducted. The AD likewise does not specify a pathway for administrative appeal or review of CASA’s approvals for equivalent parts; those processes, if any, are not described in the AD itself.

Implication for operators

• Operators should treat the AD as mandatory and assume that failure to comply may attract enforcement, given the AD’s issuance under CAR 1998 and the operational instruction that cracked assemblies must be replaced before further flight. Because the AD references CASA-approved equivalents, operators seeking to use non-Piper parts should procure the requisite approvals to avoid non-compliance. The AD makes replacement a precondition to continued flight in the event of detected cracking, which is an immediate and unambiguous operational constraint.

The AD expressly sits within the CAR 1998 regulatory framework and references FAA action and manufacturer service material. The AD states it is issued "under subregulation 39.1 (1) of CAR 1998," which is the statutory mechanism enabling CASA to issue mandatory airworthiness directives. The AD thereby operates as an instrument of the civil aviation regulatory regime rather than as an isolated rule.

Interaction with CAR 1998

• Statutory basis: By invoking subregulation 39.1(1) of CAR 1998, the AD adopts the regulatory authority granted by that subregulation. Any enforcement, administrative review, or penalties for non-compliance would be pursued under CAR 1998 and associated regulations and enforcement mechanisms. The AD itself does not restate those enforcement provisions; it assumes the reader understands that compliance obligations flow from the CAR statutory basis.

Interaction with manufacturer material (Piper Service Bulletin No. 682)

• The AD incorporates the "INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980" as the procedural method for inspection and replacement. That means that compliance with the AD requires following the SB’s specified procedures. The SB thus functions as a technical annex to the AD. Operators must therefore hold and apply the SB to satisfy the AD; discrepancies between the AD’s requirements and the SB would be resolved by adherence to the AD, and the AD’s explicit instruction to follow the SB makes the SB central to compliance.

Interaction with FAA AD 80-26-05

• The Background records that Amendment 1 responded to a new FAA AD which was prompted by reports of cracks in the improved design MLG inboard door hinge assemblies. The AD retains the "current repetitive inspections (contained in FAA AD 80-26-05)" and requires inspection on the improved design parts. That shows inter-regulatory influence: FAA action on the same or similar aircraft models informed CASA’s action. The AD therefore operates in parallel or in complement to the FAA AD, with CASA-specific amendments such as the inclusion of CASA-approved parts in Amendment 2.

Interaction with parts approval regimes

• The AD permits replacement with "Piper part number 47529-32 assembly (or FAA or CASA-approved equivalent part number)." This creates an interaction between the AD and the statutory/regulatory mechanisms by which CASA or the FAA approve parts. The approval regime for an equivalent part is not detailed in the AD, but the AD’s permissive language makes such approval a prerequisite to using alternative parts. That means procurement and installation choices intersect with parts approval law and administrative processes.

Interaction with prior versions of the AD

• The AD revokes AD/PA-31/93 Amdt 1. It therefore supersedes Amendment 1. Where Amendment 1 required certain inspections following FAA action, Amendment 2 retains those inspections but adds CASA-approved parts as allowable alternatives. Appendix obligations or prior compliance under the previous AD may still be relevant for scheduling inspections because Compliance 2 references "the next inspection required by the previous issue of this Directive" for aluminium/non-steel assemblies.

Interaction with maintenance and airworthiness recordkeeping law

• Although the AD does not itself specify maintenance logbook entries, the mandated inspections, replacements and "before further flight" replacement requirement will typically require operators and maintenance providers to record the work in the aircraft’s maintenance records in accordance with other statutory maintenance recordkeeping obligations under CAR 1998. The AD’s absence of a specific recordkeeping clause does not exempt operators from general maintenance record legal duties.

Matters not covered in the AD

• The AD does not specify the process for obtaining CASA approval for an equivalent part, nor does it specify how CASA’s approvals interact with foreign approvals beyond allowing FAA-approved equivalents. It does not address insurance, contractual obligations with lessors, or international operations explicitly. Those interactions will be governed by other applicable laws and contractual terms.

The AD’s document records three temporal milestones and the evolution of its content across amendments.

Original issue (effective 30 September 1980)

• The AD states that "The original issue of this Airworthiness Directive became effective on 30 September 1980." That original AD established initial obligations regarding the MLG inboard door hinge assemblies for the affected aircraft models, and it is the baseline from which later amendments were made.

Amendment 1 (effective 22 March 2001)

• Amendment 1 was issued in response to a new FAA AD prompted by reports of cracks in improved design MLG inboard door hinge assemblies. The Background notes that Amendment 1 retained the current repetitive inspections contained in FAA AD 80-26-05 and required inspection on the improved design parts. Amendment 1 became effective on 22 March 2001. The AD/PA-31/93 Amdt 2 document states that it revokes AD/PA-31/93 Amdt 1; therefore Amendment 1’s measures are superseded by Amendment 2. The text indicates that Amendment 1 responded to FAA action, suggesting a cross‑jurisdictional regulatory response dynamic.

Amendment 2 (effective 19 April 2001; notified 21 March 2001)

• This document is Amendment 2 and it became effective on 19 April 2001. It was signed by the CASA delegate on 9 March 2001 and "notified in the Commonwealth of Australia Gazette on 21 March 2001." The Background states Amendment 2 is issued "to include CASA-approved parts as an alternative to the Piper and FAA-approved parts." In other words, the substantive change introduced by Amendment 2 relative to Amendment 1 was to broaden permissible replacement parts to include CASA-approved equivalents, in addition to Piper and FAA-approved parts. Amendment 2 also retains the inspection regimes described in Amendment 1 and the FAA AD.

Revocation and continuity

• Amendment 2 explicitly revokes Amendment 1, meaning that compliance obligations must follow Amendment 2. However Amendment 2 preserves the inspection periodicity and the focus on improved-design parts established by Amendment 1, while adding CASA-approved parts as alternatives.

Dates and formalities

• The AD records specific effective dates for each iteration, indicating the formal administrative timeline for obligations. It is signed by the CASA delegate (David Alan Villiers) on 9 March 2001, which evidences the delegation of authority and the signature date. The notification in the Commonwealth Gazette is recorded as 21 March 2001 even though the AD’s stated effective date is 19 April 2001. Amendment 1’s effective date (22 March 2001) sits between the Gazette notification and Amendment 2’s effective date; the chronology indicates an active period in March-April 2001 when CASA issued, notified and amended the directive.

Documentary references retained across amendments

• The AD maintains the reference to Piper Service Bulletin No. 682 dated 24 July 1980 and to FAA AD 80-26-05. Those references were part of the prior ADs and remain operative for the technical instructions required for compliance.

The supplied AD text does not reference any judicial decisions, appeals, or litigation arising from this directive. There are no cases named in the AD, no citations to tribunal or court proceedings, and no mention of disputes or legal challenges. The Background states that "Instances of main landing gear inboard door hinge failure have occurred on local aircraft," and that FAA action prompted Amendment 1, but those are operational and regulatory triggers rather than litigation events.

Implications for potential litigation or dispute risk (based on what the AD sets out)

• Enforcement-related disputes: Because the AD does not specify enforcement mechanisms or penalties within its text, any dispute concerning enforcement or sanctions for non-compliance would proceed under the broader CAR 1998 framework and its enforcement provisions. Such disputes would therefore be litigated in the forums and by the processes applicable to enforcement actions under CAR 1998. The AD itself does not record any such actions.

• Approval of equivalent parts: Amendment 2 permits CASA-approved equivalents as alternative parts. Disputes could theoretically arise over whether a proposed alternative part is properly "CASA-approved." The AD does not describe the approval process or the grounds for denial, so if a supplier or operator contests CASA’s refusal to approve an alternative part, that contest would be litigable under the administrative law regime for CASA decisions. The AD does not provide a dispute resolution mechanism for parts approvals.

• Operational grounding and contractual disputes: The requirement to replace cracked assemblies "before further flight" creates immediate grounding obligations. Where replacement parts are unavailable or there is disagreement about whether a crack exists, commercial disputes with lessors, insurers or operators could arise. The AD does not address contractual or indemnity issues; conflicts of that kind would be resolved in the applicable commercial or insurance channels and possibly in court if contested. The AD contains no record of such litigation.

• Judicial review: Because the AD is an administrative instrument issued under CAR 1998, judicial review of the AD’s lawfulness could theoretically be sought in the relevant courts, but the AD text includes no record of any such proceedings. The AD’s content indicates the regulator exercised a safety-based regulatory power in response to reported hinge failures and FAA action; challenges to such regulatory action would require grounds outside the instrument itself (for example, procedural fairness, ultra vires claims, or irrationality), none of which are referenced in the AD.

In short, the AD contains no litigation history. Any litigated issues arising from its implementation, enforcement or parts-approval decisions are not documented in the AD and would be matters external to the instrument.

Timing nuances and the two-tier inspection regime

• The Compliance section contains timing instructions that vary by part material and part number and which use "whichever occurs first" and "whichever occurs later" formulations. For assemblies that are Piper part number 47529-32 (or approved equivalent) the initial inspection is "upon accumulating 2,000 hours TIS on the MLG inboard door hinge assembly or within the next 100 hours TIS after 19 April 2001, whichever occurs later." That means if an assembly already has more than 2,000 hours TIS at the effective date, the initial inspection might be delayed until beyond 100 hours after 19 April 2001, depending on whether the later condition applies. By contrast, for aluminium/non-steel assemblies the inspection is required "at the next inspection required by the previous issue of this Directive or within the next 100 hours TIS after 19 April 2001 whichever occurs first," and thereafter every 100 hours TIS. Failure to correctly calculate which clause applies can lead to missed inspections.

Serial-number specificity and applicability risk

• The Applicability table is highly granular, listing many serial-number ranges across multiple model variants. Misreading or misapplying the serial ranges could result in a failure to treat an aircraft as subject to the AD when it is, or vice versa. Operators must verify the aircraft serial number precisely against the table. The AD’s coverage is not simply "all PA-31 series" but the enumerated serial ranges; a mistaken assumption of model-level coverage can produce non-compliance.

Material and part-number distinctions

• Requirement 2 specifically targets "any aluminium MLG inboard door hinge assembly that is not Piper part number 47529-32 (or FAA or CASA-approved equivalent part number) or any other assembly that is not made of steel." That is a complex logical construction: it captures aluminium assemblies that are not the Piper 47529-32 part, and it also captures any assembly that is not steel. Operators who have assemblies of differing materials must pay attention to the material and part-number data in maintenance records to identify the correct inspection interval and obligations. Misclassifying the assembly material or part number alters the inspection interval from 2,000 hours TIS to 100 hours TIS.

Immediate grounding where cracks are found

• The AD requires replacement "before further flight after the inspection" where a cracked assembly is found. This is an absolute operational constraint: the aircraft is not permitted to fly until the assembly is replaced with the specified part or an approved equivalent. Operators must therefore plan for potential grounding, parts procurement and installation lead times.

Dependence on Piper Service Bulletin No. 682

• Inspections and replacements must be "in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980." If the operator does not hold or correctly interpret that Service Bulletin, or if the SB is ambiguous, the AD nonetheless requires compliance with those instructions. Operators should secure the SB, confirm its content, and ensure that maintenance personnel are trained to perform the inspection as described.

Parts approval and procurement

• Amendment 2 permits CASA-approved equivalents as alternatives. However the AD does not describe how CASA approval is obtained for an equivalent part. Operators seeking to use a substitute part must engage the CASA approval process; use of an unapproved substitute would be non-compliant. If parts supply is constrained, operators face a practical risk: replacement is mandatory before further flight after detection of cracking, yet securing a Piper PN 47529-32 or an approved equivalent may require lead time, potentially leaving aircraft grounded.

Revocation of Amendment 1 and transitional obligations

• Amendment 2 revokes Amendment 1. The AD references inspections required by the previous issue of the Directive when specifying timing for aluminium/non-steel assemblies ("Inspect at the next inspection required by the previous issue of this Directive or within the next 100 hours time-in-service after 19 April 2001 whichever occurs first"). Operators who complied with Amendment 1 must carefully reconcile prior schedules with the new Amendment 2 instructions to avoid double-counting or omission.

Gazette notification and effective dates

• The AD records different dates: the AD was signed on 9 March 2001, notified in the Commonwealth Gazette on 21 March 2001, and became effective on 19 April 2001. Operators should not assume that Gazette notification and effective date are coincident. The Compliance section uses 19 April 2001 in its timing language. Misreading these dates could result in mis-timed inspections.

No penalty matrix in text

• The AD contains no explicit list of penalties for non-compliance within its text, so operators may be tempted to interpret that as lax enforcement. That would be a mistake. The AD’s authority under CAR 1998 places it within an enforceable statutory regime; absence of explicit penalties in the AD does not mean non-enforcement.

Recordkeeping expectations

• Although the AD does not set out recordkeeping specifics, the "before further flight" requirement and the integration of Service Bulletin instructions mean that maintenance records must evidence compliance. Failure to produce records in the event of an audit or enforcement action could be problematic even though the AD itself does not state specific record-entry requirements.

Step 1 , Determine applicability precisely

• Check the aircraft model and serial number against the Applicability table in the AD. The AD lists precise serial-number ranges for each model variant (e.g. PA-31: 31-2 through 31-900 and 31-7300901 through 31-8312019; PA-31-350: 31-5001 through 31-5004 and 31-7305005 through 31-8553002; etc.). Only aircraft with serial numbers that fall within the listed ranges are subject to this AD. Confirm the airframe serial number in the aircraft’s documentation and maintenance logbook.

Step 2 , Identify current hinge assembly part number and material

• Examine maintenance records and the physical assembly to determine whether the MLG inboard door hinge assembly is Piper PN 47529-32, an FAA- or CASA-approved equivalent, an aluminium assembly that is not PN 47529-32, or another non-steel assembly. The AD’s inspection interval depends on this classification: PN 47529-32 (or approved equivalents) follow the 2,000-hour inspection interval scheme; aluminium or other non-steel assemblies that are not PN 47529-32 follow the 100-hour inspection interval scheme.

Step 3 , Obtain and apply Piper Service Bulletin No. 682

• The AD requires inspections and replacements to be performed "in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980." Acquire that Service Bulletin, ensure maintenance personnel read and understand the INSTRUCTIONS section, and apply the SB’s prescribed inspection procedures, inspection points, and any specified inspection methods (visual, eddy current, dye penetrant, etc.) as described in the SB.

Step 4 , Schedule inspections according to Compliance timing

• If the hinge assembly is PN 47529-32 or an FAA/CASA-approved equivalent: schedule the initial inspection upon accumulating 2,000 hours TIS on the hinge assembly or within the next 100 hours TIS after 19 April 2001, whichever occurs later; thereafter schedule inspections at intervals not exceeding 2,000 hours TIS (Compliance 1).
• If the hinge assembly is aluminium and not PN 47529-32 (or not an FAA/CASA-approved equivalent), or any assembly not made of steel: schedule the initial inspection at the next inspection required by the previous issue of the Directive or within the next 100 hours TIS after 19 April 2001 whichever occurs first, and thereafter at intervals not exceeding 100 hours TIS (Compliance 2).
• Document inspection scheduling in the aircraft maintenance program and coordinate with maintenance providers to ensure inspections are performed timely.

Step 5 , Conduct inspections and act on findings

• Perform the inspection per the SB’s INSTRUCTIONS. Inspect "all hinges and hinge attachment angles in the MLG inboard door hinge assembly" as required (Requirement 1(a) and 2(a)). If any cracked hinge assembly is detected, replace it with Piper PN 47529-32 or an FAA- or CASA-approved equivalent assembly (Requirement 1(b) and 2(b)).
• Replacement is required "before further flight after the inspection" where the cracked assembly was found. Plan for parts procurement and downtime accordingly to avoid prolonged grounding.

Step 6 , Procure approved replacement parts

• Replace cracked assemblies with Piper part number 47529-32 or with an FAA- or CASA-approved equivalent part number. Because Amendment 2 explicitly allows CASA-approved parts as alternatives, if you intend to use a non-Piper part you must ensure it holds an FAA or CASA approval as an equivalent part number. Verify approval documentation and retain evidence of approval for audit.

Step 7 , Record and certify compliance

• Although the AD does not state detailed record-entry requirements, recordkeeping obligations under CAR 1998 and standard maintenance logbook practices will require that inspections and replacements be documented. Record the inspection date, findings, part numbers of replaced assemblies, approval documentation for equivalents where applicable, and certification by the authorised maintenance personnel. Ensure the maintenance release or certificate of release to service complies with applicable regulatory requirements.

Step 8 , Liaise with CASA where necessary

• If you intend to use a CASA-approved alternative part, engage with CASA early to secure the required approval before installing that part. If there is uncertainty about interpretation of the AD’s timing language or about how prior compliance with Amendment 1 affects current scheduling (notably the Compliance 2 reference to "the next inspection required by the previous issue of this Directive"), seek clarification from CASA to avoid misapplication.

Step 9 , Plan for operational impacts

• Because replacement for cracked assemblies is required before further flight, plan for parts availability and scheduled maintenance windows. For aluminium/non-steel assemblies subject to 100-hour intervals, ensure that maintenance resources are aligned with the increased inspection frequency to avoid non-compliance or unexpected grounding.

Step 10 , Maintain traceability of parts and compliance history

• Keep records of all parts installed, including part numbers and approval evidence for any FAA- or CASA-approved equivalents. Such documentation will support compliance demonstration in audits or if enforcement action is initiated. Keep copies of Piper Service Bulletin No. 682 and note that the AD requires adherence to its INSTRUCTIONS section.

Practical checklist summary

• Verify aircraft is within applicable serial-number range.
• Determine hinge assembly part number and material.
• Obtain Piper Service Bulletin No. 682 and follow the INSTRUCTIONS section.
• Schedule inspections according to the appropriate Compliance clause (2000-hour vs 100-hour intervals as applicable).
• Replace any cracked assembly with Piper PN 47529-32 or FAA/CASA-approved equivalent, and do not fly the aircraft until replacement is completed.
• Document inspections, findings, replacements, and approvals in maintenance records.
• If using a CASA-approved equivalent part, secure and retain CASA approval documentation.

Adhering to these steps will align operational practice with the explicit mandates of AD/PA-31/93 Amdt 2 as set out in the supplied directive.