AD/PC-12/46 - Landing Gear Components

This AD is structured around a narrow set of airworthiness concepts: applicability, identification by part numbers and serial numbers, inspection trigger, mandated replacement, service bulletin as the technical remedy, and a finite compliance window. Each of these elements is explicit in the document.

Applicability: The AD sets out precise models and serial ranges. It applies to Model PC‑12 and PC‑12/45 aircraft with serial numbers MSN 101 through MSN 471 and MSN 473 through MSN 482, when equipped with the landing gear components listed (Applicability). The components are identified by part numbers and by the assembly serial numbers that are relevant to the action: Nose Landing Gear assemblies P/N 532.20.12.038 and 532.20.12.039 with serial numbers AM 001-AM 045 and AM 048-AM 054; Main Landing Gear assemblies P/N 532.10.12.049 and 532.10.12.050 with serial numbers AM 001-AM 027, AM 029-AM 045, AM 047-AM 050, AM 052 and AM 053; and Main Landing Gear shock absorber assemblies P/N 532.10.12.175 with a detailed range of AM serials (Applicability). The AD therefore combines aircraft MSN ranges and component part and serial‑number identification to narrow scope.

Inspection trigger and test: The action required is an inspection to determine whether the assembly serial numbers start with the letters AM (Requirement). The AD sets a simple binary test: if the assembly serial number does not start with AM, no further action is required; if it does start with AM, the component(s) must be replaced within the compliance time (Requirement).

Remedy: Replacement parts and the method of replacement are specified by reference to Pilatus PC‑12 Service Bulletin No. 32‑16 dated 11 March 2004 or later FOCA approved revisions (Requirement). The AD also instructs a pre‑installation check against two other ADs/service bulletins (AD/PC‑12/30 and AD/PC‑12/38), making compliance with earlier directives a precondition for reinstallation (Requirement).

Time measurement: The compliance metric is expressed in hours time in service with both an operational limit and an absolute calendar cut‑off: inspect within 300 hours time in service after 7 July 2005 but not later than 31 December 2005 (Compliance). The AD also states the effective date, 7 July 2005 (Compliance).

Causal finding: The Background section identifies the causal mechanism: an improper cadmium plating process applied to certain high strength steel landing gear parts potentially caused hydrogen embrittlement, decreasing specified fatigue life and potentially leading to failure and landing gear collapse during operation. The AD relies on the manufacturer’s investigation to justify the mandated inspections and replacements (Background).

Cross‑references: The AD cross‑references external approvals and actions: it requires the specific Pilatus service bulletin or later FOCA approved revisions for replacement parts and references Switzerland FOCA AD HB‑2005‑168 (Requirement, Note). It also requires checks against AD/PC‑12/30 and AD/PC‑12/38 before installing any assembly (Requirement).

Incentive and compliance logic: The AD creates an incentive for operators to identify affected parts and to replace them within the stated window, or to face the operational risk of unaddressed hydrogen embrittlement. The form of the AD , identifying by serial number prefix and by part number , limits the universe of potentially affected parts, reducing the population which must be inspected. The technical remediation is outsourced to the manufacturer's service bulletin and FOCA approval process, shifting the technical specification to documents external to the AD text (Requirement).

Owners and operators of Pilatus PC‑12 and PC‑12/45 aircraft within the specified serial number ranges are the primary parties directly affected. The Applicability section identifies the aircraft models (Model PC‑12 and PC‑12/45) and aircraft serial number ranges (MSN 101 through MSN 471 and MSN 473 through MSN 482). The effect attaches only when the aircraft is equipped with the specified landing gear assemblies and shock absorber assemblies (Applicability). If an aircraft within the MSN ranges does not have the enumerated part numbers installed, the AD does not impose further action for those installations.

Maintenance organisations and certificated mechanics will be affected insofar as they must perform the inspections and, where required, the replacements consistent with the AD. The Requirement states simply "Perform an inspection ... to determine if the serial numbers start with the letters AM." The AD therefore imposes an operational duty to inspect components and to execute replacements where necessary.

Suppliers of Pilatus parts, including authorised Pilatus service centres and parts distributors, are affected because the AD prescribes replacement using parts and procedures in Pilatus PC‑12 Service Bulletin No. 32‑16 dated 11 March 2004 or later FOCA approved revisions. Those suppliers will be engaged to supply replacement parts and may be asked to confirm that parts supplied comply with the SB and FOCA approvals.

Regulators are implicated in a procedural sense. The AD refers to FOCA (Switzerland) approvals and to FOCA AD HB‑2005‑168; it also carries the signature of a CASA delegate. The AD effectively requires operators to follow a remedy that is contingent on Pilatus documentation and FOCA approvals. While the text does not specify enforcement agents or penalties, the issuance by the Civil Aviation Safety Authority makes CASA the issuing regulator (signed by David Villiers, Delegate of the Civil Aviation Safety Authority).

Aircraft lessors, insurers and operators who manage fleets will be secondarily affected because inspection and replacement can impose scheduling, downtime and parts procurement demands. The compliance window (300 hours TIS after 7 July 2005, but not later than 31 December 2005) compresses the time in which operators must arrange inspections and procure replacements.

Aircraft not captured by the specified MSNs, part numbers or serial‑number prefixes are not affected by the AD as written. The AD’s test is strictly serial number based: "If the assembly serial numbers do not start with the letters AM, no further action is required" (Requirement). This creates a bright‑line for applicability at the component serial‑number level.

The AD also affects repair and installation practices as it requires a check against AD/PC‑12/30 and AD/PC‑12/38 "Before installing any assembly, check compliance with AD/PC‑12/30 (PC‑12 SB 32‑012) and AD/PC‑12/38 (PC‑12 SB 32‑015)" (Requirement). That instruction links the current AD to prior directives and therefore affects the sequence and documentation of compliance for maintenance providers.

The AD imposes a small set of concrete duties and leaves other matters unaddressed in the text. The principal duties are these.

Inspection duty: The AD requires an inspection of the Nose Landing Gear assemblies P/N 532.20.12.038 or 532.20.12.039, the Main Landing Gear assemblies P/N 532.10.12.049 or 532.10.12.050, and the Main Landing Gear shock absorber assembly P/N 532.10.12.175 to determine if the assembly serial numbers start with the letters AM (Requirement). This inspection must be performed within the compliance window (Compliance). The text establishes the inspection as a mandatory act for affected aircraft and parts; it does not specify who (owner, operator, or maintenance organisation) must carry out the inspection, but the Requirement language "Perform an inspection" frames it as an operational obligation.

Replacement duty: If, during the required inspection, an assembly has a serial number starting with AM, the AD requires that, within the compliance time, the affected component(s) be replaced with new parts as specified in Pilatus PC‑12 Service Bulletin No. 32‑16 dated 11 March 2004 or later FOCA approved revisions (Requirement). The AD therefore constrains the remedy to replacement with parts and procedures documented in the referenced service bulletin or its FOCA‑approved revisions.

Pre‑installation duty: The AD explicitly requires that, before installing any assembly, personnel must check compliance with two earlier ADs or service bullets: AD/PC‑12/30 (PC‑12 SB 32‑012) and AD/PC‑12/38 (PC‑12 SB 32‑015) (Requirement). That creates a duty to verify that installation will not contravene prior ADs, embedding a sequencing requirement.

Compliance timing: The AD prescribes the time limits: inspect within 300 hours time in service after 7 July 2005 but not later than 31 December 2005; and it declares that the AD becomes effective on 7 July 2005 (Compliance). These are unqualified timing constraints.

Rights and omissions in the text: The AD provides no express right of appeal, no stated exemption mechanisms, and no explicit administrative process for deviation or alternative means of compliance within the text provided. It does not itself describe penalties, sanctions, or enforcement mechanisms. It does not expressly allocate the financial burden for inspections or replacement; the document confines itself to technical and timing mandates and to reference to the Pilatus service bulletin and FOCA approved revisions for remedy.

Reference and method: The AD delegates the technical method for replacement to the manufacturer's service bulletin and to later FOCA approved revisions (Requirement). That means the substantive technical instructions, tolerances and replacement procedures are outside the AD text and are to be followed as specified in the referenced documents.

Cause and justification: The AD records the manufacturer's finding about improper cadmium plating and hydrogen embrittlement that could reduce fatigue life and lead to landing gear collapse (Background). The presence of that causal finding is the textual justification for the inspection and replacement duties.

Practical implication of duties: Owners and operators must schedule and document the inspection within the stated service‑time limit, determine whether serial numbers begin "AM", and if so proceed to replace parts per the mandated service bulletin or approved revisions, while checking for compliance with the two earlier ADs before reinstallation. The AD text creates clear technical steps, but does not spell out administrative compliance records, cost allocation or exceptions.

The AD text itself does not state any penalties, fines, enforcement procedures or sanctions. The document sets out the technical and timing requirements , inspection within 300 hours time in service after 7 July 2005 but not later than 31 December 2005, replacement with parts per Pilatus Service Bulletin No. 32‑16 or later FOCA approved revisions, and pre‑installation checks against AD/PC‑12/30 and AD/PC‑12/38 (Requirement; Compliance) , but it contains no express enforcement clause or mention of consequences for non‑compliance within the text provided.

Because the AD is issued by the Civil Aviation Safety Authority (signed by David Villiers, Delegate of the Civil Aviation Safety Authority), it is a regulatorally issued airworthiness directive. The AD text documents the required actions and the dates on which those actions must occur (Compliance), and it identifies the technical references that must be followed for replacement (Requirement). The AD does not, within the supplied text, describe processes for certification of compliance, maintenance release particulars, or how CASA will verify adherence. There is also no statement in the AD text about an alternative means of compliance, exemptions, administrative review or appeal process.

The AD refers to Pilatus Service Bulletin No. 32‑16 dated 11 March 2004 or later FOCA approved revisions (Requirement) and refers to Switzerland FOCA AD HB‑2005‑168 (Note). It also requires a pre‑installation check with AD/PC‑12/30 and AD/PC‑12/38 (Requirement). Those cross‑references implicate other technical and regulatory documents, but the AD as provided does not indicate which agency enforces compliance nor what administrative or civil penalties, if any, attach to non‑compliance.

Given the absence of penalties or enforcement detail in the AD text, persons affected should treat the AD as a mandatory technical directive whose non‑compliance may have safety consequences and, depending on external regulatory frameworks not included in the text, may carry enforcement consequences administered by the regulator. The AD itself, as reproduced, is silent on those procedural enforcement details.

Within its own text, this AD creates explicit linkages to other airworthiness directives and to foreign regulator approvals. It instructs operators to use Pilatus Service Bulletin No. 32‑16 dated 11 March 2004, or later FOCA approved revisions, as the required method for replacement (Requirement). It also requires that, before installing any assembly, operators check compliance with two earlier ADs: AD/PC‑12/30 (PC‑12 SB 32‑012) and AD/PC‑12/38 (PC‑12 SB 32‑015) (Requirement). The AD further notes that Switzerland FOCA AD HB‑2005‑168 is referred to (Requirement, Note).

These cross‑references create a chain of technical and regulatory dependencies. Compliance with AD/PC‑12/46 depends on the content and status of the referenced service bulletin and on the content and status of the earlier ADs. The AD therefore operates as part of a network of airworthiness directives and service documentation: it does not stand alone technically because the method of replacement and installation checks are specified by other documents.

The AD's reference to "FOCA approved revisions" and to Switzerland FOCA AD HB‑2005‑168 indicates an interaction between CASA's directive and approvals or mandates from the Swiss Federal Office of Civil Aviation (FOCA). The AD requires compliance with Pilatus SB No. 32‑16 or "later FOCA approved revisions", which means that any later changes to the SB that are FOCA‑approved are treated as acceptable methods of compliance under this AD (Requirement). The AD thus recognises foreign regulator approvals as relevant to domestic compliance.

Beyond these explicit references, the text does not identify or incorporate other domestic legislation, such as civil aviation safety statutes, maintenance standards or enforcement regulations. The AD does not itself set out administrative enforcement mechanisms, penalties, or inspection regimes under domestic law; it is limited to technical requirements and cross‑references. Therefore, any interaction with civil aircraft regulation, certification processes, or enforcement frameworks beyond the AD depends on statutory and regulatory regimes not reproduced in this text.

Where an operator must "check compliance with AD/PC‑12/30 and AD/PC‑12/38 before installing any assembly" (Requirement), the AD creates an operational sequencing requirement and ties compliance documentation for this AD into the compliance status of earlier ADs. This can affect record‑keeping and maintenance release procedures, because an installation would be non‑compliant under AD/PC‑12/46 unless the checks against the two earlier ADs are performed and satisfied.

The AD also refers to pilot or maintenance actions measured in "hours time in service" (Compliance). That operational metric interacts in practice with operators' flight logs and maintenance scheduling regimes, and thus indirectly interacts with other domestic rules about maintenance records and continued airworthiness, although those provisions are not included in the AD text.

In short, AD/PC‑12/46 explicitly interacts with other ADs and with FOCA approvals by making those documents the technical route for compliance and by requiring cross‑checks prior to installation. The text does not set out wider statutory enforcement mechanisms or administrative procedures; those interactions are left to the broader regulatory framework not shown in the reproduced AD.

The AD as supplied sets out the date of signature and the effective date but includes no internal amendment or revision history in the text provided. The document records that it "becomes effective on 7 July 2005" (Compliance) and that it was signed by David Villiers, Delegate of the Civil Aviation Safety Authority, on 25 May 2005. The AD states the Pilatus Service Bulletin target date (Pilatus PC‑12 Service Bulletin No. 32‑16 dated 11 March 2004) and also permits "later FOCA approved revisions" of that service bulletin to be used for replacement (Requirement). That permission provides an implicit mechanism for later technical revisions to the remedy to be adopted without issuing a formal amendment to this AD text, provided such revisions are FOCA approved.

The AD also includes a "Note" that Switzerland FOCA AD HB‑2005‑168 is referred to (Requirement, Note). The presence of that cross‑reference indicates contemporaneous related action by the Swiss regulator, but the AD text does not record any change, supersessions, or historical amendments to AD/PC‑12/46 itself.

No subsequent amendments, extensions, or withdrawals are recorded in the supplied text. The AD identifies related previous ADs , AD/PC‑12/30 and AD/PC‑12/38 , by reference when specifying pre‑installation checks (Requirement), but it does not indicate whether AD/PC‑12/46 supersedes or amends earlier ADs. The text simply requires checks of compliance with those earlier ADs before making installations.

Where the AD permits "later FOCA approved revisions" of Pilatus SB No. 32‑16 to be used, that creates a technical path for updated procedures to be accepted without reissuing an amending AD. Practically, therefore, revisions to the service bulletin approved by FOCA can alter the method of compliance for operators without textual amendment of the AD itself, but the AD text does not contain a record of any such revisions or of their dates.

If the reader requires a formal amendment record (dates of any amendments, supersessions, or cancellations), the supplied AD text contains none. The only dates present within the AD are the service bulletin date (11 March 2004), the signature date (25 May 2005), the effective date (7 July 2005) and the latest calendar compliance cut‑off (31 December 2005). There is no within‑text amendment history beyond these entries.

The AD text contains no litigation history. It does not record any legal challenges, court proceedings, appeals or disputes related to AD/PC‑12/46. The document is a technical regulatory directive that records technical findings and prescribes inspection and replacement actions; it does not include or reference any judicial determinations or litigation outcomes.

The absence of litigation history in the supplied text means that this AD, as reproduced, provides no case law to illuminate its interpretation, contested scope, procedural regularity or enforcement. It also does not provide any record of administrative appeals or revisions that might have arisen through dispute resolution processes.

For those seeking precedent or judicial interpretation of AD/PC‑12/46, the AD itself gives no pointers. The only references in the AD are to related service bulletins and to FOCA AD HB‑2005‑168; none of these references in the AD text are accompanied by litigation information. Any litigation history, if it exists, would therefore need to be sought outside the text provided.

The AD contains several practical traps and precise conditions that can be overlooked if a reader skims the text.

Serial‑number specificity and prefix test: The inspection criterion is precisely stated: inspect the assemblies and determine if the assembly serial numbers start with the letters "AM" (Requirement). If the assembly serial numbers do not start with "AM", the AD states "no further action is required" (Requirement). The test is therefore a prefix test, not a range test alone; however, the Applicability also lists explicit serial ranges of AM‑prefixed assemblies. Operators must therefore verify both that their aircraft model and MSN fall within Applicability and that the installed parts carry the AM serials listed. Failure to verify serial prefixes on each assembly could lead to unnecessary replacement or missed affected parts.

Discontinuous serial ranges: For each part number the Applicability lists particular serial ranges and skips. For example, Nose Landing Gear assemblies P/N 532.20.12.038 and .039 list AM 001-AM 045 and AM 048-AM 054 (Applicability). Main landing gear assemblies and shock absorber assemblies have multiple, sometimes non‑contiguous serial ranges. Operators must check the exact AM serial numbers listed; assuming that all AM prefixes indicate an affected part without checking the exact serial ranges could be overbroad.

Dual criteria for applicability: The AD ties applicability to three elements , aircraft model and MSN range, part number, and assembly serial numbers (Applicability). An operator must have all three in scope for action to be required. Missing any one of these might mean the AD does not apply. For example, an aircraft within the MSN range but with different part numbers installed may not be subject to the replacement requirement, though the inspection requirement language suggests the initial check is the serial‑number check.

Compliance timing has two constraints: The AD requires inspection within 300 hours time in service after 7 July 2005, and also sets an absolute calendar deadline of 31 December 2005 (Compliance). Operators must manage both the tracked hours metric and the calendar date. Failing to meet either deadline appears out of compliance with the AD's timing requirements.

Replacement method is externally specified: The AD mandates replacement "with new parts as specified in Pilatus PC‑12 Service Bulletin No. 32‑16 dated 11 March 2004 or later FOCA approved revisions" (Requirement). The AD does not itself reproduce the technical steps, parts numbers for replacement components, or acceptance criteria; operators must obtain and follow the service bulletin and any FOCA approved revisions. Assuming the AD itself contains all necessary technical detail would be an error.

Pre‑installation checks required: The AD requires that "Before installing any assembly, check compliance with AD/PC‑12/30 (PC‑12 SB 32‑012) and AD/PC‑12/38 (PC‑12 SB 32‑015)" (Requirement). Failing to perform that check prior to reinstallation could lead to non‑compliance with this AD even if the replacement was performed.

FOCA approvals matter: The AD permits "later FOCA approved revisions" of the Pilatus SB to be used. That means later changes to the SB are not automatically acceptable unless they are FOCA‑approved revisions. Using a later SB revision not FOCA approved would risk being inconsistent with the AD’s directive.

No enforcement details in the text: The AD does not specify penalties, record‑keeping requirements or enforcement processes (Penalties and enforcement). Treating the AD as self‑contained and assuming it details enforcement procedures would be a mistake; compliance practitioners must refer to the broader regulatory framework for enforcement specifics.

Timing of effective date versus signature date: The AD is signed 25 May 2005 but states that it "becomes effective on 7 July 2005" (Compliance). Operators should note the effective date as the starting point for the "300 hours time in service after 7 July 2005" compliance measurement.

Reference to foreign AD: The AD notes that Switzerland FOCA AD HB‑2005‑168 is referred to (Requirement, Note). Assuming FOCA AD HB‑2005‑168 is identical in every respect to AD/PC‑12/46 would be an assumption; the AD simply "refers" to it.

Document sourcing for replacement: Because replacement is mandated by reference to an external service bulletin, ensure that you obtain the exact SB version dated 11 March 2004 or confirm FOCA approval of any later revisions before relying on them. The AD makes the SB the technical source of replacement instructions; neglecting to obtain the SB or to verify FOCA approval status of later revisions is a practical risk.

Compliance under this AD is a sequence of discrete, document‑linked steps. The AD text itself prescribes the steps and the timing; implementers must follow them exactly.

1. Confirm aircraft applicability. Check the aircraft model and MSN. The AD applies to Model PC‑12 and PC‑12/45 aircraft with serial numbers MSN 101 through MSN 471 and MSN 473 through MSN 482 when equipped with the listed landing gear components (Applicability). If the aircraft is not within these MSN ranges, the AD’s actions as stated do not apply.

2. Identify installed landing gear assemblies and serial numbers. For each aircraft that falls within the MSNs, determine whether it is equipped with any of the specified parts:

   • Nose Landing Gear assemblies P/N 532.20.12.038 and 532.20.12.039 with serial numbers AM 001-AM 045 and AM 048-AM 054;
   • Main Landing Gear assemblies P/N 532.10.12.049 and 532.10.12.050 with serial numbers AM 001-AM 027, AM 029-AM 045, AM 047-AM 050, AM 052 and AM 053;
   • Main Landing Gear shock absorber assemblies P/N 532.10.12.175 with the enumerated AM serial number ranges (Applicability). Physically inspect nameplates/tags and maintenance records to capture the exact assembly serial numbers.

3. Perform the serial‑number test. The AD’s inspection is a binary test: determine whether the assembly serial numbers start with "AM" (Requirement). If an affected assembly’s serial number does not start with AM, "no further action is required" for that assembly (Requirement).

4. Schedule inspection within the compliance window. The inspection must occur within 300 hours time in service after 7 July 2005 and not later than 31 December 2005 (Compliance). Ensure the aircraft’s time in service records are consulted and schedule the inspection so that both the hours‑based and calendar deadlines are satisfied.

5. If any assembly has an AM serial prefix within the listed ranges, replace within the compliance time. The AD mandates that affected component(s) be replaced with new parts "as specified in Pilatus PC‑12 Service Bulletin No. 32‑16 dated 11 March 2004 or later FOCA approved revisions" (Requirement). Obtain the service bulletin and any later FOCA approved revisions and follow their replacement procedures exactly.

6. Before installation, check compliance with prior ADs. The AD requires that before installing any assembly, persons must "check compliance with AD/PC‑12/30 (PC‑12 SB 32‑012) and AD/PC‑12/38 (PC‑12 SB 32‑015)" (Requirement). Perform and document these checks and ensure all prerequisites in those ADs are met.

7. Document actions carefully. Although the AD text does not itself set out record‑keeping requirements, the AD specifies discrete actions and timing. Maintain contemporaneous records of: the serial‑number inspections, the dates and aircraft hours at inspection, copies of Pilatus SB No. 32‑16 and any FOCA approved revisions used, records of replaced parts (part numbers and serial numbers), and documentation showing checks against AD/PC‑12/30 and AD/PC‑12/38 prior to installation.

8. Source replacement parts in accordance with the SB and FOCA approvals. Because the AD conditions replacement on the Pilatus service bulletin (and FOCA approved revisions), ensure that replacement parts and procedures are consistent with those documents. Verify that any later SB revisions you intend to use have FOCA approval, as the AD limits acceptable later versions to those FOCA approved revisions (Requirement).

9. Coordinate maintenance scheduling and logistics. The compliance window is finite and, for some operators, may require prioritising affected aircraft for inspection and replacement. Plan for potential aircraft downtime, parts lead times and the need for certified maintenance resources to carry out replacements in line with the SB instructions.

10. Maintain awareness of related directives. The AD refers to FOCA AD HB‑2005‑168 and to earlier ADs. Ensure your compliance file includes the referenced FOCA AD and AD/PC‑12/30 and AD/PC‑12/38 so that pre‑installation checks and cross‑referenced requirements are satisfied (Requirement, Note).

11. Confirm effective date and measure hours appropriately. The compliance time is measured from 7 July 2005; record the aircraft hours at that date or calculate the hours in service since that date to ensure the inspection is conducted within 300 TIS hours or by 31 December 2005, whichever occurs first (Compliance).

12. Seek the service bulletin and FOCA approvals from authorised sources. The AD points you to Pilatus PC‑12 Service Bulletin No. 32‑16 dated 11 March 2004 and to later FOCA approved revisions. Ensure you obtain the exact documents and approvals before proceeding with replacement work.

This sequence follows precisely the wording of the AD. The AD does not provide alternative means of compliance or exemptions within the text supplied; if an operator considers an alternative technical solution, the AD does not itself provide an approval mechanism. Any such request would need to be pursued through the appropriate regulatory channels outside the provided text.