AD/CL-600/35 Amdt 2 - Main Landing Gear Main Fitting

The AD operates through a small set of concrete technical and regulatory concepts, stated in the AD’s own fields. First, applicability: the AD is limited to Model CL-600-2B19 aircraft "equipped with main landing gear fittings part number 601R85001-3 and 601R85001-4 (MDI part number 17064-101, -102, -103, and -104)." That establishes the population of aircraft to which the directive applies. Second, the corrective action is a parts replacement: install "new main fittings, part number 601R85001-83 and 601R85001-84 (MDI part number 17064-107 and17064-108)" and to do so "in accordance with Bombardier Service Bulletin (SB) 601R-32-093 original issue, SB 601R85001 Revision A, or SB 601R85001 Revision B, or later Transport Canada approved revision." The AD therefore ties compliance to specified manufacturer documentation and recognises Transport Canada approvals of later revisions.

Third, the AD creates a temporal obligation: "Unless already accomplished, before 30 September 2007" establishes a mandatory completion date. Fourth, the AD creates a substitution effect for prior requirements: "Incorporation of the new main fittings terminates the need to comply with Parts I, II, III, IV, and V of AD CF-1999-32R3; and with Parts I, II, and III of associated AD CF-2004-18R1." That is a rule of legal substitution: once the new fittings are fitted, the earlier enumerated Parts of those specific ADs no longer apply to that aircraft.

The Background material introduces operational and inspection concepts. It identifies a specific failure mechanism: "a circumferential crack ... at the radius between the fitting cylinder area and the upper attachment lug for the shock strut." It records three reported occurrences, and describes Amendment 1’s prior mitigations: servicing of shock struts; repetitive inspection for nitrogen pressure and visible chrome dimensions; and an allowance to increase eddy current inspection intervals under certain conditions. The AD therefore relies on a conventional regulatory toolkit: initial mitigations (servicing and inspections), then, following further analysis and alignment with Transport Canada, a mandatory part-replacement remedy intended to eliminate the root cause.

Finally, the AD references inter-jurisdictional alignment: Amendment 2 is "issued in response to a revision of the related Transport Canada AD, which requires replacement of affected main landing gear main fittings." The AD therefore coordinates CASA action with an equivalent Transport Canada directive and links compliance documentation to Bombardier Service Bulletins and Transport Canada-approved revisions of those bulletins.

This AD directly affects owners and operators of Bombardier (Canadair) CL-600-2B19 aircraft that are fitted with the specified main landing gear main fitting part numbers. The Applicability field is explicit: it applies to "Model CL-600-2B19 aircraft, equipped with main landing gear fittings part number 601R85001-3 and 601R85001-4 (MDI part number 17064-101, -102, -103, and -104)." Any aircraft lacking those part numbers are not within the applicability as stated.

Practically, the primary economic actors who will bear the workload and costs are the aircraft owners and operators of affected aeroplanes. They must arrange for the parts replacement to be performed in accordance with the Bombardier Service Bulletin language cited, or a later Transport Canada approved revision. Maintenance organisations and approved maintenance engineers who perform the work will be engaged to carry out the physical replacement and any required documentation associated with SB compliance. The AD names specific replacement part numbers 601R85001-83 and 601R85001-84 (MDI 17064-107 and -108) as the fitment that must be installed.

Regulatory actors are also implicated. The AD is a CASA instrument, signed by "David Villiers, Delegate of the Civil Aviation Safety Authority," and it references Transport Canada ADs and Transport Canada approval of Service Bulletin revisions. Therefore, the AD operates in a regulatory ecosystem involving CASA, Transport Canada, and Bombardier as the OEM whose SBs are the method of compliance.

There are consequences for ongoing maintenance regimes for affected aircraft. The Background explains that earlier coursetakings (Amendment 1) required servicing and repetitive inspection of shock struts for nitrogen pressure and visible chrome dimensions, and allowed eddy current inspection interval changes in some cases. Those continuing inspection and servicing obligations remain in place until the replacement is carried out, after which "Incorporation of the new main fittings terminates the need to comply with" specifically enumerated parts of two earlier ADs. Therefore maintenance planners and reliability engineers must track which aircraft have had replacements and which remain subject to repetitive inspections.

Finally, stakeholders in supply and logistics are affected: the AD requires specific replacement part numbers and references MDI part numbers, which means procurement, parts availability and lead times will be relevant to operators seeking to meet the "before 30 September 2007" deadline. The AD also requires adherence to manufacturer SBs or later Transport Canada-approved revisions, so document control and approval status of SB revisions are relevant to maintenance organisations deciding what constitutes an acceptable method of compliance.

Duties

• Replacement obligation. The core duty imposed by AD/CL-600/35 Amdt 2 is to "Replace the affected main landing gear main fittings with new main fittings, part number 601R85001-83 and 601R85001-84" and to perform that replacement "in accordance with Bombardier Service Bulletin (SB) 601R-32-093 original issue, SB 601R85001 Revision A, or SB 601R85001 Revision B, or later Transport Canada approved revision." This is a direct, prescriptive technical duty and it specifies both the parts and the method (the SBs or later approved revisions).

• Timing duty. The replacement must be completed "Unless already accomplished, before 30 September 2007." The AD itself became effective on 30 August 2007, so the compliance timeline is clear in the instrument.

• Interim obligations. Prior to replacement, affected aircraft remain subject to the measures introduced in Amendment 1: servicing of main landing gear shock struts; repetitive inspection of the shock strut for nitrogen pressure and visible chrome dimensions; and eddy current inspection requirements (with an allowance under Amendment 1 to increase intervals under certain conditions). The Background explicitly records that Amendment 1 added these servicing and inspection tasks.

• Documentation and method duty. Compliance is linked to specific Bombardier Service Bulletins or later Transport Canada approved revisions. That imposes a duty to follow those SB procedures or ensure that any revision used is Transport Canada approved.

Rights and legal effects

• Termination of prior duties. The AD explicitly states that "Incorporation of the new main fittings terminates the need to comply with Parts I, II, III, IV, and V of AD CF-1999-32R3; and with Parts I, II, and III of associated AD CF-2004-18R1." This is a right or relief for operators who complete the replacement: after replacement, those specific earlier AD obligations no longer apply. The text is prescriptive and limited to the enumerated Parts of those earlier ADs.

• Choice of approved SB revision. The AD allows compliance by following one of several SB conditions: SB 601R-32-093 original issue, SB 601R85001 Revision A, SB 601R85001 Revision B, or "later Transport Canada approved revision." That gives operators and maintenance organisations some choice, provided the revision they follow is an approved method under the AD’s terms.

• No penalty text in this AD. The AD does not itself set out enforcement penalties or sanctions in the text supplied; it prescribes the corrective actions, the effective date and compliance deadline, and the terminating effect on prior AD parts when the replacement is performed. The AD is signed by CASA's delegate, which indicates regulatory authority for the instrument.

Operational implications

• Operators must identify affected aircraft by verifying installed part numbers against the Applicability listing and confirm whether replacement has already been accomplished.

• Maintenance providers must ensure they have the correct replacement parts (601R85001-83 and -84, MDI 17064-107 and -108), the correct procedures per the applicable SB revision, and documentation of compliance to show that specified prior AD parts are no longer required where replacement has been executed.

• Recordkeeping follows implicitly: to exercise the termination effect over prior ADs, operators will need evidence that the new fittings were installed in accordance with the SBs cited.

All duties and rights summarised above are taken directly from the AD's Applicability, Requirement, Compliance and Background fields.

The AD, as supplied, does not contain an express penalties clause or an enforcement schedule setting out sanctions for non-compliance. The text includes an effective date ("This Amendment becomes effective on 30 August 2007") and a compliance deadline ("Unless already accomplished, before 30 September 2007") and is signed by the CASA Delegate, David Villiers, which establishes it as a formal regulatory instrument. However, the AD itself does not specify fines, suspensions, or criminal offences in the language provided.

Given the absence of express penalty provisions in the AD text, the instrument nevertheless creates legally binding technical obligations for the aircraft and operators within the stated Applicability. The presence of an effective date and a deadline indicates that the obligations are time-bound and enforceable in the regulatory sense customary for airworthiness directives. The AD also makes clear the method of compliance by referencing specific Bombardier Service Bulletins or later Transport Canada-approved revisions. For those actors subject to the AD, the text imposes a mandatory technical requirement to be completed by the stated date, and completion confers the benefit of terminating certain prior AD obligations (explicitly listed).

If one needs to understand the formal enforcement tools and sanctions that CASA may deploy for non-compliance, that material is not contained in this AD and must be sought in the broader statutory and regulatory framework that empowers CASA and describes enforcement actions. The AD does not itself make those enforcement mechanisms explicit.

Operationally, the AD creates an immediate compliance management task for operators: determine applicability, schedule replacement before the deadline, and document compliance. Where replacement is not accomplished by the deadline, the AD's plain terms leave the operator in the state of non-compliance with a CASA AD; the AD text does not include an amnesty, staged compliance, or conditional waivers in the supplied wording.

The AD records a history of previous remedial measures (Amendment 1) comprising servicing and repetitive inspections, and states that those measures remain required until replacement is carried out. From an enforcement perspective, inspectors or auditors relying on the AD will be able to check aircraft status against the Applicability and Requirement fields and against records of SB-compliant replacement work. The AD’s explicit statement that incorporation of the new fittings terminates the need to comply with named Parts of earlier ADs provides a clear compliance indicator for audit purposes: presence of the new part numbers and SB-compliant documentation should demonstrate that the earlier inspection and servicing obligations need no longer be performed for that aircraft.

In short, the AD sets mandatory technical obligations and deadlines and defines the method of compliance, but it does not set out penalties or enforcement procedures within the text provided. The regulatory authority of the document is established by signature and effective date language; the specifics of enforcement and sanctioning mechanisms are not contained in the AD as supplied.

The AD explicitly positions itself within a network of prior ADs and regulatory documents. It refers to and modifies the effect of earlier CASA-referenced and Transport Canada airworthiness directives. The AD states that performing the mandated replacement "terminates the need to comply with Parts I, II, III, IV, and V of AD CF-1999-32R3; and with Parts I, II, and III of associated AD CF-2004-18R1." That is a direct legal interaction: AD/CL-600/35 Amdt 2 supersedes or substitutes for specified obligations in those enumerated Parts of specified prior ADs when the new fittings are installed.

The AD also explicitly aligns with a revision of a related Transport Canada AD. The Background records that "Amendment 2 is issued in response to a revision of the related Transport Canada AD, which requires replacement of affected main landing gear main fittings." Therefore this CASA AD functions as a domestic instrument that mirrors or adopts an outcome mandated by a foreign regulator (Transport Canada) for the type-certificated aircraft whose manufacturer is Bombardier (Canadair). By referencing Transport Canada-approved revisions of Bombardier Service Bulletins as acceptable methods of compliance, the AD creates cross-recognition of Transport Canada approvals in the method-of-compliance chain: operators may use "later Transport Canada approved revision[s]" of the Bombardier SBs to comply.

Service Bulletins and approved revisions are the procedural interface between manufacturer documentation and regulator-approved compliance. The AD names specific Bombardier SBs: SB 601R-32-093 (original issue) and SB 601R85001 Revision A and Revision B. The AD permits "or later Transport Canada approved revision," which integrates the Transport Canada approval process into the method-of-compliance regime for CASA. This creates a procedural interdependence: if a later SB revision is to be used, it must have Transport Canada approval to be acceptable under this AD.

The AD also interacts with prior remedial AD content. Amendment 1, referenced in the Background, had added servicing and repetitive inspection requirements and allowed the eddy current inspection interval to be increased under certain conditions. Those prior obligations remain in force for aircraft that have not yet had the replacement. Once the replacement is fitted as required by Amendment 2, the AD expressly terminates the need to continue complying with the enumerated Parts of the earlier ADs. That creates a legal switching rule: either continue the earlier inspection/regime until replacement, or replace and move out of the earlier regime.

The AD establishes a temporal interaction with earlier ADs: the original AD became effective on 24 February 2000; subsequent amendments adjusted inspection regimes and servicing in Amendment 1; Amendment 2 (the present text) adopts the replacement requirement consistent with the Transport Canada AD revision and sets a new effective date and compliance deadline. The document therefore modifies the operator’s compliance pathway depending on whether or not the new fitting is installed by the stated date.

Finally, the AD is silent on broader statutory enforcement provisions, penalties, exemptions, or administrative appeal rights. Those matters would be governed by the overarching aviation safety legislation and CASA’s regulatory framework outside this AD. In the text provided, the only explicit inter-law interactions are with AD CF-1999-32R3, AD CF-2004-18R1 and Transport Canada ADs and approvals, and with the Bombardier Service Bulletins as the prescribed compliance mechanism.

The AD text records a concise amendment timeline and the substantive changes between versions. The original Airworthiness Directive was issued and became effective on 24 February 2000, as stated in the AD: "The original issue of this Airworthiness Directive became effective on 24 February 2000." Amendment 1 followed and is not reproduced in full here, but the Background summarises Amendment 1’s content: it "added servicing of the main landing gear shock struts, and repetitive inspection of the shock strut for nitrogen pressure and visible chrome dimensions." Amendment 1 also "allowed the eddy current inspection interval to be increased under certain conditions."

Amendment 2 is the present instrument and is dated in the header as "AD/CL-600/35 Amdt 2" with the issue dated "9/2007" and the signature block showing "11 July 2007" as the delegate signing date and "This Amendment becomes effective on 30 August 2007." The compliance statement sets "Unless already accomplished, before 30 September 2007" as the mandatory completion deadline.

Substantively, the amendments evolved from inspection and servicing measures in Amendment 1 to a mandatory parts-replacement solution in Amendment 2. The Background explains the reason for that progression: there were "three reported cases of premature failure of the main landing gear main fitting" and further investigation "revealed that, under certain conditions, a mis-serviced shock strut could lead to premature failure of the fitting." Amendment 1 therefore introduced servicing and inspection to mitigate risk. Subsequent developments, including a revision by Transport Canada to require replacement, prompted Amendment 2 to adopt replacement as the definitive corrective action and to terminate certain prior AD obligations upon replacement.

Amendment 2 also aligns CASA action with Transport Canada’s revised AD direction, as stated in the Background: "Amendment 2 is issued in response to a revision of the related Transport Canada AD, which requires replacement of affected main landing gear main fittings." Thus the AD’s amendment history shows a regulatory shift from interim mitigations (servicing, inspections) to a mandated hardware replacement in response to accumulating incident reports and external regulator decisions.

The document contains header repetitions and formatting lines, but the substantive amendment milestones recorded are: original AD effective 24 February 2000; Amendment 1 (content summarised) introduced servicing and repetitive inspections and adjusted eddy current inspection intervals; Amendment 2 (this text), dated July 2007 and effective 30 August 2007 with a compliance deadline of 30 September 2007, mandates replacement with specified new part numbers and specifies SBs or Transport Canada-approved SB revisions as the method of compliance.

The AD as provided contains no references to litigation, court decisions, injunctions, administrative appeals, or case law. The supplied text is narrowly focused on technical applicability, required corrective action, compliance timing, and background facts concerning reported failures and prior amendment content. It records the original AD effective date and the dates and rationale for amendments, but it does not report any legal disputes, appeals against the AD, or litigation outcomes.

Because the instrument does not include any litigation history, one cannot draw from this document any factual claims about judicial review, successful challenges, or enforcement proceedings arising from this AD. The only legal indicia in the text are the formalities of issuance: the signature block "David Villiers, Delegate of the Civil Aviation Safety Authority" and the effective and compliance dates. There is no further material in the AD that describes litigation, contested administrative proceedings, or precedent decisions.

For practitioners who require a record of any legal challenges or enforcement actions relating to AD/CL-600/35 or its amendments, the AD itself does not supply that information. Any such litigation history would need to be sourced from external records (court registries, administrative tribunal files, CASA enforcement notices), but those are outside the text provided here. Within the instrument, the history is limited to the operational chronology and the technical reasons for amendments: reports of three premature failures, Amendment 1’s interim measures, and Amendment 2’s replacement mandate to align with Transport Canada’s revised AD.

• Narrow applicability by part number. The AD applies specifically to "Model CL-600-2B19 aircraft, equipped with main landing gear fittings part number 601R85001-3 and 601R85001-4 (MDI part number 17064-101, -102, -103, and -104)." Operators must verify the exact part numbers installed on each aircraft. Mistaken identification of part numbers could lead to unnecessary work or failure to comply where required. The AD is precise about affected old part numbers and new replacement part numbers (601R85001-83 and 601R85001-84; MDI 17064-107 and -108).

• Method-of-compliance nuance. The AD requires replacement "in accordance with Bombardier Service Bulletin (SB) 601R-32-093 original issue, SB 601R85001 Revision A, or SB 601R85001 Revision B, or later Transport Canada approved revision." That phrasing creates two potential pitfalls. First, if a maintenance provider uses a later SB revision, the later revision must be Transport Canada approved to be acceptable under this AD. Second, the AD names multiple SB documents by number and revision; using an incorrectly numbered or non-approved revision could be treated as non-compliant with the AD.

• Timing differences between effective date and compliance deadline. The AD "becomes effective on 30 August 2007" but sets a compliance deadline "before 30 September 2007." That yields a relatively short window between effective date and compliance deadline (one month). For affected operators, logistical issues , parts availability, maintenance slotting, ferry flights or grounding , could complicate meeting that window. The AD’s text does not provide staged deadlines or extensions.

• Interim obligations remain until replacement. Amendment 1 added servicing and repetitive inspections (shock strut servicing, nitrogen pressure checks and visible chrome dimension inspection, and eddy current inspections). Those measures were not abolished by Amendment 2 for aircraft that have not yet had the replacement installed. Operators must therefore continue to perform those interim inspections and servicing until the replacement occurs or risk being out of compliance.

• Replacement terminates specified prior AD parts only. The AD does not state a blanket termination of all prior AD obligations; it expressly terminates "Parts I, II, III, IV, and V of AD CF-1999-32R3" and "Parts I, II, and III of associated AD CF-2004-18R1." That termination effect is limited to those enumerated Parts and those specific ADs. Operators must ensure they understand which prior AD obligations cease on replacement and which, if any, remain applicable.

• The AD does not spell out enforcement penalties. The instrument provides effective and compliance dates but does not include penalty language or enforcement procedures in the text supplied. This heightens the importance of confirming enforcement and compliance reporting expectations with CASA or relevant regulatory guidance outside the AD text.

• Source alignment with Transport Canada. The AD states Amendment 2 was issued "in response to a revision of the related Transport Canada AD, which requires replacement of affected main landing gear main fittings." Operators should note that the CASA AD is aligned with Transport Canada’s position, and that the AD explicitly recognises Transport Canada-approved SB revisions as acceptable for compliance. Operators dealing with non-standard SB revisions should check that any deviation has the requisite Transport Canada approval.

• Recordkeeping to obtain termination effect. The AD’s termination of prior AD Parts turns on "Incorporation of the new main fittings." Practically, operators will need documentary proof that the replacement was accomplished "in accordance with" an acceptable SB revision to justify ceasing the earlier inspections and servicing. Absent such records, audits and inspections may treat the aircraft as still subject to the earlier AD Parts.

• Ambiguity around "mis-serviced shock strut." The Background notes that "under certain conditions, a mis-serviced shock strut could lead to premature failure of the fitting." That phrase flags an operational risk area but does not define "mis-serviced." Operators should be cautious to apply SB instructions precisely and to ensure servicing is performed by personnel authorised and competent to follow Bombardier SB procedures.

This AD prescribes a concrete, time-bound compliance pathway. The following steps restate the AD’s requirements as a practical checklist directly derived from the AD text.

1. Identify affected aircraft.

   • Verify each aircraft’s main landing gear main fitting part numbers. The AD applies to Model CL-600-2B19 aircraft fitted with part numbers 601R85001-3 and 601R85001-4 (MDI part numbers 17064-101, -102, -103, and -104). If those part numbers are not installed, the AD’s replacement requirement, as stated, does not apply to that aircraft.

2. Plan for replacement parts and SB documentation.

   • Procure replacement parts: 601R85001-83 and 601R85001-84 (MDI part numbers 17064-107 and 17064-108).
   • Obtain and review the applicable Bombardier Service Bulletin: SB 601R-32-093 (original issue), SB 601R85001 Revision A, SB 601R85001 Revision B, or a later Transport Canada-approved revision. The AD mandates adherence to those SBs or a later Transport Canada-approved revision as the method of compliance.

3. Schedule work to meet the deadline.

   • The AD states: "Unless already accomplished, before 30 September 2007." Ensure the replacement is completed before that date. Note that the Amendment became effective on 30 August 2007, so the window between effective date and compliance deadline is limited.

4. Maintain interim actions until replacement is complete.

   • If replacement has not yet been completed, continue to comply with the servicing and repetitive inspections introduced by Amendment 1: servicing of the main landing gear shock struts, repetitive inspection of shock struts for nitrogen pressure and visible chrome dimensions, and any eddy current inspection regime in force. Amendment 1 also allowed increases in eddy current inspection intervals "under certain conditions"; ensure your ongoing inspection programme is consistent with the terms of Amendment 1 until replacement is carried out.

5. Execute replacement in accordance with the SB.

   • Have an appropriately authorised maintenance organisation perform the replacement and follow the procedural steps, torque values, inspections and tests described in the Bombardier SB or Transport Canada-approved revision used as the method of compliance.

6. Document the replacement and SB compliance.

   • Create a maintenance record that identifies the aircraft serial, the removed part numbers (601R85001-3 and/or 601R85001-4), the installed replacement part numbers (601R85001-83 and/or 601R85001-84; MDI 17064-107 and -108), the SB revision followed, dates of work, signatures of certifying engineers, and any test results or inspection records required by the SB. This documentation will be the basis for exercising the AD’s termination effect upon prior AD Parts.

7. Assert termination of prior AD obligations where applicable.

   • After completing the replacement "in accordance with" an acceptable SB, operators can rely on the AD’s express language that "Incorporation of the new main fittings terminates the need to comply with Parts I, II, III, IV, and V of AD CF-1999-32R3; and with Parts I, II, and III of associated AD CF-2004-18R1." Maintain the records stated above to support the decision to cease the specified prior AD activities.

8. Confirm SB revision approval status if not using named revisions.

   • If intending to use a Bombardier SB revision that post-dates the listed revisions, confirm that the revision is approved by Transport Canada, as the AD accepts "later Transport Canada approved revision[s]" as an acceptable method of compliance. Keep documentary evidence of Transport Canada approval with maintenance records.

9. Verify no additional CASA reporting requirements are omitted.

   • The AD text itself does not set out post-compliance reporting steps beyond the replacement and termination statement. However, keep maintenance logs, SB compliance paperwork, and certification entries available for CASA inspection and for the operator’s own quality and continuing airworthiness records.

10. Track fleet status.

• Maintain a fleet register that records which aircraft have had the replacement fitted and which are still subject to the earlier servicing and inspection regime of Amendment 1. This tracking ensures that inspections and servicing are not discontinued prematurely and that the termination relief is not applied incorrectly.

All steps above flow directly from the AD’s Applicability, Requirement, Compliance and Background statements. The AD is precise about the part numbers, the accepted SBs or Transport Canada-approved revisions, the effective date, and the compliance deadline. Ensure that maintenance actions follow the SB procedures exactly and that documentation is retained to evidence compliance and to support the stated termination of specified prior AD Parts.